git filter-repo example (saved for myself, use at your own risk)

git-filter-repo.sh

git filter-repo --force --replace-refs delete-no-add --commit-callback '
    if commit.author_email == b"old_email@domain":
        commit.author_email = b"new_private_email@domain"
        commit.author_name = b"username"
        commit.committer_email = b"new_private_email@domain"
        commit.committer_name = b"username"
'