Use ssh key

Edit .git/config

[core]
    repositoryformatversion = 0
    filemode = true
    bare = false
    logallrefupdates = true
    sshCommand = "ssh -i ~/.ssh/my_key"

Rebase

git rebase --root -i

Undo

git rebase --abort

Amend

Change commit author.

git commit --amend --author="bnad <me@domain.xyz>" --no-edit