diff --git a/kokoro/macos/objectivec_cocoapods_integration/build.sh b/kokoro/macos/objectivec_cocoapods_integration/build.sh
index 8f3c9b4c15..f96d2899d9 100755
--- a/kokoro/macos/objectivec_cocoapods_integration/build.sh
+++ b/kokoro/macos/objectivec_cocoapods_integration/build.sh
@@ -6,7 +6,6 @@
 cd $(dirname $0)/../../..
 
 # Prepare worker environment to run tests
-KOKORO_INSTALL_COCOAPODS=yes
 source kokoro/macos/prepare_build_macos_rc
 
 ./tests.sh objectivec_cocoapods_integration
diff --git a/kokoro/macos/prepare_build_macos_rc b/kokoro/macos/prepare_build_macos_rc
index 2db706b12c..ef428fcda3 100755
--- a/kokoro/macos/prepare_build_macos_rc
+++ b/kokoro/macos/prepare_build_macos_rc
@@ -19,58 +19,6 @@ export DEVELOPER_DIR=/Applications/Xcode_11.3.app/Contents/Developer
 export CC=gcc
 export CXX=g++
 
-##
-# Brew: update, then upgrade the installed tools to current version and install
-# some needed ones not in the Kokoro base image. This ensure current versions
-# of CMake, autotools, etc.
-
-# But first...
-#
-# The transitive deps of the installed tools need protobuf, but Kokoro manually
-# installed it outside of brew so it needs to be removed so brew can install the
-# tools (and a newer version of protobuf). g/kokoro-users/7FRvQMUdN40 about why
-# it is a manual install vs. a brew install in the first place.
-sudo rm -rf \
-    /usr/local/include/google/protobuf \
-    /usr/local/bin/protoc
-# Likewise, updating python can have issues because of some existing binaries.
-sudo rm -rf \
-    /usr/local/bin/2to3* \
-    /usr/local/bin/idle3* \
-    /usr/local/bin/pip3 \
-    /usr/local/bin/pydoc3* \
-    /usr/local/bin/python3* \
-    /usr/local/bin/pyvenv*
-
-git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core fetch --unshallow
-git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask fetch --unshallow
-
-# This is needed to fix a conflict between the ilmbase and imath packages,
-# which seem to conflict with each other by both trying to install
-# libImath.dylib.
-brew unlink ilmbase
-
-brew update
-brew upgrade
-
-##
-# Install Ruby
-
-if [[ "${KOKORO_INSTALL_RUBY:-}" == "yes" ]] ; then
-  brew install ruby
-fi
-
-##
-# Install Cocoapods
-
-if [[ "${KOKORO_INSTALL_COCOAPODS:-}" == "yes" ]] ; then
-  # The existing cocoapods was installed via gem, but that doesn't work well
-  # with the overlap in deps with things managed by brew (errors around ruby
-  # versions, etc.); so remove it and install in via brew instead.
-  gem uninstall -a "$(gem list | grep cocoapods | cut -d ' ' -f 1)"
-  brew install cocoapods
-fi
-
 ##
 # Install Tox
 
diff --git a/kokoro/macos/ruby23/build.sh b/kokoro/macos/ruby23/build.sh
index 9317838781..5a29a997fc 100755
--- a/kokoro/macos/ruby23/build.sh
+++ b/kokoro/macos/ruby23/build.sh
@@ -6,7 +6,6 @@
 cd $(dirname $0)/../../..
 
 # Prepare worker environment to run tests
-KOKORO_INSTALL_RUBY=yes
 KOKORO_INSTALL_RVM=yes
 source kokoro/macos/prepare_build_macos_rc
 
diff --git a/kokoro/macos/ruby24/build.sh b/kokoro/macos/ruby24/build.sh
index 51bb2e603b..10ac85f7a4 100755
--- a/kokoro/macos/ruby24/build.sh
+++ b/kokoro/macos/ruby24/build.sh
@@ -6,7 +6,6 @@
 cd $(dirname $0)/../../..
 
 # Prepare worker environment to run tests
-KOKORO_INSTALL_RUBY=yes
 KOKORO_INSTALL_RVM=yes
 source kokoro/macos/prepare_build_macos_rc
 
diff --git a/kokoro/macos/ruby25/build.sh b/kokoro/macos/ruby25/build.sh
index ba2d0a4d19..48c894081b 100755
--- a/kokoro/macos/ruby25/build.sh
+++ b/kokoro/macos/ruby25/build.sh
@@ -6,7 +6,6 @@
 cd $(dirname $0)/../../..
 
 # Prepare worker environment to run tests
-KOKORO_INSTALL_RUBY=yes
 KOKORO_INSTALL_RVM=yes
 source kokoro/macos/prepare_build_macos_rc
 
diff --git a/kokoro/macos/ruby26/build.sh b/kokoro/macos/ruby26/build.sh
index 5a4c243222..1b94fe1b55 100755
--- a/kokoro/macos/ruby26/build.sh
+++ b/kokoro/macos/ruby26/build.sh
@@ -6,7 +6,6 @@
 cd $(dirname $0)/../../..
 
 # Prepare worker environment to run tests
-KOKORO_INSTALL_RUBY=yes
 KOKORO_INSTALL_RVM=yes
 source kokoro/macos/prepare_build_macos_rc
 
diff --git a/kokoro/macos/ruby27/build.sh b/kokoro/macos/ruby27/build.sh
index b1529b9da0..baebdb792a 100755
--- a/kokoro/macos/ruby27/build.sh
+++ b/kokoro/macos/ruby27/build.sh
@@ -6,7 +6,6 @@
 cd $(dirname $0)/../../..
 
 # Prepare worker environment to run tests
-KOKORO_INSTALL_RUBY=yes
 KOKORO_INSTALL_RVM=yes
 source kokoro/macos/prepare_build_macos_rc
 
diff --git a/kokoro/macos/ruby30/build.sh b/kokoro/macos/ruby30/build.sh
index 6b9bfb3215..b1e0641c96 100755
--- a/kokoro/macos/ruby30/build.sh
+++ b/kokoro/macos/ruby30/build.sh
@@ -6,7 +6,6 @@
 cd $(dirname $0)/../../..
 
 # Prepare worker environment to run tests
-KOKORO_INSTALL_RUBY=yes
 KOKORO_INSTALL_RVM=yes
 source kokoro/macos/prepare_build_macos_rc