diff --git a/chroot_version_hooks.d/161_cleanup_sdk_binpkgs b/chroot_version_hooks.d/161_cleanup_sdk_binpkgs
deleted file mode 100644
index c4775ee..0000000
--- a/chroot_version_hooks.d/161_cleanup_sdk_binpkgs
+++ /dev/null
@@ -1,8 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Prune orphaned binpkgs from the SDK that are never used by builders or devs.
-# See https://crbug.com/927122 for more details.
-
-exec sudo rm -rf /packages/
diff --git a/chroot_version_hooks.d/162_post_protobuf_upgrade b/chroot_version_hooks.d/162_post_protobuf_upgrade
deleted file mode 100644
index 16f93ee..0000000
--- a/chroot_version_hooks.d/162_post_protobuf_upgrade
+++ /dev/null
@@ -1,31 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Clean local portage caches. This is necessary if there are
-# cros_workon packages.
-sudo rm -rf /var/cache/portage/* /build/*/var/cache/portage/*
-
-# Clean board packages.
-for board_root in /build/* ; do
-  board=${board_root##*/}
-  [[ "${board}" == "bin" || "${board}" == "dev" || \
-     "${board}" == "proc" ]] && continue
-
-  # Find packages using  either protobuf or grpc.
-  PKGS=( $(qdepends-${board} -qCN -Q dev-libs/protobuf && \
-         qdepends-${board} -qCN -Q net-libs/grpc | sort -u))
-  if [[ ${#PKGS[@]} -eq 0 ]]; then
-    continue
-  fi
-
-  echo "Cleaning packages using protobuf or grpc from ${board}"
-  PKGDIR=$(portageq-${board} envvar PKGDIR)
-  cd "${PKGDIR}"
-  # Remove existing binary packages.
-  for pkg in "${PKGS[@]}"; do
-    sudo rm -f "${pkg}"-[0-9]*.tbz2
-  done
-  # Unmerge all packages using either protobuf or grpc.
-  qmerge-${board} -Uqy "${PKGS[@]}"
-done
diff --git a/chroot_version_hooks.d/163_use_postsubmit_binpkgs b/chroot_version_hooks.d/163_use_postsubmit_binpkgs
deleted file mode 100644
index a8ccdcd..0000000
--- a/chroot_version_hooks.d/163_use_postsubmit_binpkgs
+++ /dev/null
@@ -1,19 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Force regeneration of every board configuration in order to include the
-# postsubmit builders as binpkg sources.
-# crbug.com/898996
-
-for board_root in /build/*; do
-  board_name=${board_root##*/}
-  if [[ -e "/build/${board_name}/etc/make.conf.board" ]]; then
-    /mnt/host/source/chromite/bin/setup_board \
-        --board=${board_name} \
-        --skip-board-pkg-init \
-        --skip-chroot-upgrade \
-        --regen-configs &
-  fi
-done
-wait
diff --git a/chroot_version_hooks.d/164_post_protobuf_upgrade b/chroot_version_hooks.d/164_post_protobuf_upgrade
deleted file mode 120000
index 127de13..0000000
--- a/chroot_version_hooks.d/164_post_protobuf_upgrade
+++ /dev/null
@@ -1 +0,0 @@
-162_post_protobuf_upgrade
\ No newline at end of file
diff --git a/chroot_version_hooks.d/165_clean_libbrillo_so b/chroot_version_hooks.d/165_clean_libbrillo_so
deleted file mode 100644
index 5e9b1bf..0000000
--- a/chroot_version_hooks.d/165_clean_libbrillo_so
+++ /dev/null
@@ -1,9 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Some library and package config files of libbrillo were created at
-# src_install() phase into the cache. It prevents overwriting when we switch to
-# create those files at src_compile with the user privilege.
-
-sudo rm -rf /var/cache/portage/* /build/*/var/cache/portage/*
diff --git a/chroot_version_hooks.d/166_gtest_upgrade b/chroot_version_hooks.d/166_gtest_upgrade
deleted file mode 100644
index 7db485a..0000000
--- a/chroot_version_hooks.d/166_gtest_upgrade
+++ /dev/null
@@ -1,18 +0,0 @@
-# Copyright 2014 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# gtest/gmock 1.7 is not binary compatible with the 1.6 version since
-# some internal symbols exposed in the .so file changed. The portage
-# cache in /build/$BOARD/var/cache/portage/chromeos-base will keep files
-# even if the ebuild is recompiled with the new gtest, so we need to remove
-# those files as well.
-#
-
-for sysroot in /build/* /; do
-  (
-  info "Cleaning /var/cache/portage/chromeos-base from ${sysroot}"
-  sudo rm -rf "${sysroot}"/var/cache/portage/chromeos-base
-  ) &
-done
-wait
diff --git a/chroot_version_hooks.d/167_remove_svn b/chroot_version_hooks.d/167_remove_svn
deleted file mode 100644
index cc31348..0000000
--- a/chroot_version_hooks.d/167_remove_svn
+++ /dev/null
@@ -1,32 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Purge subversion (and its unique deps) from the SDK as no one uses it anymore.
-# https://crbug.com/982351
-
-PKGS=(
-  dev-vcs/subversion
-  net-libs/neon
-  net-libs/serf
-
-  # Some boards might need these for other packages (e.g. apache), but our build
-  # system will just pull them back in on demand, so purging should be safe.
-  dev-libs/apr
-  dev-libs/apr-util
-)
-
-# Clear the SDK first.
-echo "Clearing subversion (and deps) from the SDK"
-sudo qmerge -Uqy "${PKGS[@]}" &
-
-# Clean board packages.
-for board_root in /build/*; do
-  board=${board_root##*/}
-  if [[ -d "${board_root}/var/db/pkg" ]]; then
-    echo "Clearing subversion (and deps) from ${board}"
-    sudo qmerge-${board} -Uqy "${PKGS[@]}" &
-  fi
-done
-
-wait
diff --git a/chroot_version_hooks.d/168_python34_cleanup b/chroot_version_hooks.d/168_python34_cleanup
deleted file mode 100644
index 71673be..0000000
--- a/chroot_version_hooks.d/168_python34_cleanup
+++ /dev/null
@@ -1,36 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Drop Python 3.4 from the SDK as we've moved to Python 3.6 everywhere.
-# Make sure 3.6 is installed in case this is an old chroot.
-
-echo "Cleaning up Python 3.4 to migrate to 3.6"
-
-export CLEAN_DELAY=0
-
-# Install python 3.6 if the sdk is out of date.
-if ! python3.6 --version >&/dev/null; then
-  sudo emerge -ug dev-lang/python:3.6
-fi
-
-# Point python3 to the new version.
-sudo eselect python update --python3
-
-# Remove python 3.4 from the system.
-sudo emerge -Cq dev-lang/python:3.4
-
-# Remove java-config if needed to avoid circular deps.
-reinstall_java="false"
-if ! python3.6 -c 'import java_config_2' >&/dev/null; then
-  reinstall_java="true"
-  sudo emerge -Cq dev-java/java-config
-fi
-
-# Upgrade portage itself finally.
-sudo emerge -Ugqv sys-apps/portage
-
-# Reinstall java-config in case we purged it.
-if [[ "${reinstall_java}" == "true" ]]; then
-  sudo emerge -ugqv dev-java/java-config
-fi
diff --git a/chroot_version_hooks.d/169_deleted_binhosts_cleanup b/chroot_version_hooks.d/169_deleted_binhosts_cleanup
deleted file mode 100644
index a8097cd..0000000
--- a/chroot_version_hooks.d/169_deleted_binhosts_cleanup
+++ /dev/null
@@ -1,18 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Force regeneration of every board configuration in order to clean out
-# old binhosts. crbug.com/965244
-
-for board_root in /build/*; do
-  board_name=${board_root##*/}
-  if [[ -e "/build/${board_name}/etc/make.conf.board" ]]; then
-    /mnt/host/source/chromite/bin/setup_board \
-        --board=${board_name} \
-        --skip-board-pkg-init \
-        --skip-chroot-upgrade \
-        --regen-configs &
-  fi
-done
-wait
diff --git a/chroot_version_hooks.d/170_deleted_binhosts_cleanup b/chroot_version_hooks.d/170_deleted_binhosts_cleanup
deleted file mode 120000
index 7bac7f7..0000000
--- a/chroot_version_hooks.d/170_deleted_binhosts_cleanup
+++ /dev/null
@@ -1 +0,0 @@
-169_deleted_binhosts_cleanup
\ No newline at end of file
diff --git a/chroot_version_hooks.d/171_world_set_cleanup b/chroot_version_hooks.d/171_world_set_cleanup
deleted file mode 100644
index 3ddf7b8..0000000
--- a/chroot_version_hooks.d/171_world_set_cleanup
+++ /dev/null
@@ -1,7 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Make sure the @world set is empty and doesn't contain packages we don't want
-# it to like rust.  https://crbug.com/1013967
-sudo rm -f /var/lib/portage/world
diff --git a/chroot_version_hooks.d/172_deleted_binhosts_cleanup b/chroot_version_hooks.d/172_deleted_binhosts_cleanup
deleted file mode 120000
index 7bac7f7..0000000
--- a/chroot_version_hooks.d/172_deleted_binhosts_cleanup
+++ /dev/null
@@ -1 +0,0 @@
-169_deleted_binhosts_cleanup
\ No newline at end of file
diff --git a/chroot_version_hooks.d/173_rust_slot_purge b/chroot_version_hooks.d/173_rust_slot_purge
deleted file mode 100644
index 5157ae9..0000000
--- a/chroot_version_hooks.d/173_rust_slot_purge
+++ /dev/null
@@ -1,17 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# A hack to try and unwedge some rust rebuilds.  https://crbug.com/1018589
-
-export CLEAN_DELAY=0
-
-for board_root in /build/*; do
-  board_name=${board_root##*/}
-  if [[ -d "${board_root}/var/db/pkg/dev-rust" ]]; then
-    if rust_pkgs=$(qlist-"${board_name}" -IC dev-rust); then
-      emerge-"${board_name}" -Cq ${rust_pkgs} &
-    fi
-  fi
-done
-wait
diff --git a/chroot_version_hooks.d/174_python3_sdk_default b/chroot_version_hooks.d/174_python3_sdk_default
deleted file mode 100644
index 73a382c..0000000
--- a/chroot_version_hooks.d/174_python3_sdk_default
+++ /dev/null
@@ -1,14 +0,0 @@
-# Copyright 2019 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Set Python 3 as the default implementation.
-sudo eselect python update
-
-# Install the new symlinks.  This is normally handled only when the SDK is
-# first created.
-sudo ln -sfT /mnt/host/source/chromite \
-  /usr/lib64/python3.6/site-packages/chromite
-
-# Sanity check.
-python -c 'import sys; assert sys.version_info.major >= 3'
diff --git a/chroot_version_hooks.d/175_clang-python_cleanup b/chroot_version_hooks.d/175_clang-python_cleanup
deleted file mode 100644
index 955aeeb..0000000
--- a/chroot_version_hooks.d/175_clang-python_cleanup
+++ /dev/null
@@ -1,7 +0,0 @@
-# Copyright 2020 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Remove dev-python/clang-python package which will clean-up out-dated
-# dependencies in the old chroot.
-sudo qmerge -Uqy dev-python/clang-python
diff --git a/chroot_version_hooks.d/176_binutils_fixup b/chroot_version_hooks.d/176_binutils_fixup
deleted file mode 100644
index b33c38e..0000000
--- a/chroot_version_hooks.d/176_binutils_fixup
+++ /dev/null
@@ -1,34 +0,0 @@
-# Copyright 2020 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Fix binutils headers and library conflicts when installing binutils-libs.
-# Remove symlinks to headers that are now provided by binutils-libs.
-# Note re-building binutils does not remove these symlinks so
-# a manual removal is needed to avoid merge conflicts.
-files_to_remove=(
-	/usr/include/symcat.h
-	/usr/include/plugin-api.h
-	/usr/include/bfdlink.h
-	/usr/include/bfd.h
-	/usr/include/dis-asm.h
-	/usr/include/ansidecl.h
-	/usr/include/libiberty/sort.h
-	/usr/include/libiberty/fibheap.h
-	/usr/include/libiberty/safe-ctype.h
-	/usr/include/libiberty/demangle.h
-	/usr/include/libiberty/objalloc.h
-	/usr/include/libiberty/hashtab.h
-	/usr/include/libiberty/timeval-utils.h
-	/usr/include/libiberty/splay-tree.h
-	/usr/include/libiberty/partition.h
-	/usr/include/libiberty/dyn-string.h
-	/usr/include/libiberty/libiberty.h
-	/usr/include/libiberty/floatformat.h
-	/usr/include/libiberty/ansidecl.h
-	/usr/include/libiberty.h
-)
-echo "Fixing up binutils installation"
-sudo rm -f "${files_to_remove[@]}"
-sudo emerge -ugq sys-devel/binutils-config
-sudo emerge -ugq sys-libs/binutils-libs
diff --git a/chroot_version_hooks.d/177_purge_crosutils b/chroot_version_hooks.d/177_purge_crosutils
deleted file mode 100644
index 30e258e..0000000
--- a/chroot_version_hooks.d/177_purge_crosutils
+++ /dev/null
@@ -1,6 +0,0 @@
-# Copyright 2020 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# This package has been removed, so make sure it's cleaned up.
-sudo qmerge -Uqy dev-util/crosutils
diff --git a/chroot_version_hooks.d/178_merge_distdir b/chroot_version_hooks.d/178_merge_distdir
deleted file mode 100644
index ff79034..0000000
--- a/chroot_version_hooks.d/178_merge_distdir
+++ /dev/null
@@ -1,46 +0,0 @@
-# Copyright 2020 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# We changed the distfile download dirs to a combined one, so move the old
-# content up to the common location.
-
-# Delete the old symlinks.
-sudo rm -f /var/lib/portage/distfiles /var/lib/portage/distfiles-target
-
-# Merge the content.
-echo "Merging old distfiles paths"
-cd /var/cache/distfiles
-for srcdir in target host; do
-  if [[ ! -d "${srcdir}" ]]; then
-    continue
-  fi
-
-  echo "  ${srcdir} ..."
-  # Merge the two git subdirs.
-  for gitdir in egit-src git3-src; do
-    mkdir -p "${gitdir}"
-    if [[ -d "${srcdir}/${gitdir}" ]]; then
-      for d in $(find "${srcdir}/${gitdir}/" -mindepth 1 -maxdepth 1 -type d \
-                   -printf '%f\n'); do
-        if [[ ! -d "${gitdir}/${d}" ]]; then
-          mv "${srcdir}/${gitdir}/${d}" "${gitdir}/" || exit 1
-        fi
-      done
-    fi
-  done
-
-  # Clear all the subdirs now that they're migrated.
-  sudo rm -rf "${srcdir}"/*/
-
-  # Merge the files.
-  rm -f "${srcdir}"/*._checksum_failure_.*
-  for f in "${srcdir}"/*; do
-    if [[ -e "${f}" && ! -e "${f##*/}" ]]; then
-      mv "${f}" ./ || exit 1
-    fi
-  done
-
-  # Delete the dir.
-  sudo rm -rf "${srcdir}" || exit 1
-done
diff --git a/chroot_version_hooks.d/179_purge_ruby b/chroot_version_hooks.d/179_purge_ruby
deleted file mode 100644
index 61be2bb..0000000
--- a/chroot_version_hooks.d/179_purge_ruby
+++ /dev/null
@@ -1,10 +0,0 @@
-# Copyright 2020 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# These packages have been removed, so make sure they're cleaned up.
-sudo qmerge -Uqy \
-  app-admin/puppet \
-  app-eselect/eselect-ruby \
-  dev-lang/ruby \
-  $(qlist -IC virtual/ruby dev-ruby/)
diff --git a/chroot_version_hooks.d/180_select_jvm b/chroot_version_hooks.d/180_select_jvm
deleted file mode 100644
index e76d71c..0000000
--- a/chroot_version_hooks.d/180_select_jvm
+++ /dev/null
@@ -1,15 +0,0 @@
-# Copyright 2020 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Specify JDK as openjdk-bin-11 upon entering chroot.
-# See crrev.com/c/2335921 for more details.
-
-# Make sure dependencies are installed for older SDKs.
-sudo emerge -qug '>=virtual/jdk-9'
-
-sudo eselect java-vm set system openjdk-bin-11
-
-# Log current state for debugging issues.
-eselect java-vm list
-whereis java
diff --git a/chroot_version_hooks.d/181_rust_cleanup b/chroot_version_hooks.d/181_rust_cleanup
deleted file mode 100644
index 6bf0fc6..0000000
--- a/chroot_version_hooks.d/181_rust_cleanup
+++ /dev/null
@@ -1,26 +0,0 @@
-# Copyright 2020 The Chromium OS Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Clean ebuilds that have been upgraded but aren't automatically removed.
-
-export CLEAN_DELAY=0
-
-to_remove=(
-  "~dev-rust/bitflags-1.1.0"
-  "~dev-rust/byteorder-1.3.1"
-  "~dev-rust/proc-macro2-1.0.8"
-  "~serde-1.0.81"
-  "~serde_derive-1.0.81"
-  "~syn-1.0.14"
-)
-
-sudo emerge -Cq "${to_remove[@]}" &
-
-for board_root in /build/*; do
-  board_name=${board_root##*/}
-  if [[ -d "${board_root}/var/db/pkg/dev-rust" ]]; then
-    emerge-"${board_name}" -Cq "${to_remove[@]}" &
-  fi
-done
-wait