changeStringsInFileInCurrentBranch.sh

#!/bin/bash

# $1 - file name
# $2 - string to find
# $3 - string to replace

git filter-branch -f --tree-filter "if [ -f $1 ];then sed -i s/$2/$3/g $1;fi"

findFilesContainingStringInBranch.sh

#!/bin/bash

# $1 - string to find
# $2 - branch name or nothing (current branch in that case)

git log -S "$1" $2 --name-only --pretty=format: -- | sort -u

replaceStringInBranch.sh

#!/bin/bash
# $1 - branch
# $2 - string to find
# $3 - string to replace with

git checkout $1
for file in $(~/findFilesContainingStringInBranch.sh "$2"); do
  echo "          Filtering file $file:"
  ~/changeStringsInFileInCurrentBranch.sh "$file" "$2" "$3"
done

replaceStringInWholeGitHistory.sh

#!/bin/bash
# $1 - string to find
# $2 - string to replace with

for branch in $(git branch | cut -c 3-); do
  echo ""
  echo ">>> Replacing strings in branch $branch:"
  echo ""
  ~/replaceStringInBranch.sh "$branch" "$1" "$2"
done