How to modify existing, unpushed commit messages?

Answer 1

You can use Git rebasing. For example, if you want to modify back to commit bbc643cd, run

$ git rebase bbc643cd^ --interactive

In the default editor, modify 'pick' to 'edit' in the line whose commit you want to modify. Make your changes and then stage them with

$ git add 

Now you can use

$ git commit --amend

to modify the commit, and after that

$ git rebase --continue

to return back to the previous head commit.