How to split an earlier git commit into multiple ones

As usual, keep having to google this, so finally writing it down here...

Last commit

Simply do git reset HEAD~ and make new commits as needed.

Commit further back

1. Perform an interactive rebase (e.g. git rebase -i main), and change the commit from pick to edit.
2. Reset the commit with git reset HEAD~.
3. Make new commits as needed.
4. Complete the rebase with git rebase --continue