Git Grep and Replace
If you want to replace a string in a bunch of files, you can use the following command:
On Linux:
git grep -l 'original_text' | xargs sed -i 's/original_text/new_text/g'
On Mac/OSX:
git grep -l 'original_text' | xargs sed -i '' -e 's/original_text/new_text/g'
Explanation
-l
limits the output to the names of the files that contain the string -e
tells sed to use extended regular expressions (needed for osx)