git commit --amend --author 'Author Name <[email protected]>' --no-edit
git rebase -i HEAD~4 -x "git commit --amend --author 'Author Name <[email protected]>' --no-edit"
pick 897fe9e simplify code a little
pick abb60f9 add new feature
exec git commit --a
Based on http://stackoverflow.com/questions/4981126/how-to-amend-several-commits-in-git-to-change-author