How to reword any git commit message

Use git rebase -i (interactive rebase) to change any commit message. The command takes

A tip about interactive rebasing
Avoid regular rebasing (adding some other branch’s commits into the history of your branch) and interactive rebasing (changing commit order, commit messages, squashing, etc.) in the same step. When you’re trying to get commits from another branch into your branch, just rebase without any adjustment/interaction. Only rebase interactively against a commit that’s already in your branch’s history (i.e. a fast-forward commit).