You’re welcome. I’m pleased to be able to help a helper.
The best Kindergarten Instruction I can offer is to back up your files! Software upgrades can break them; editing can break them; hardware failure can break them.
To do the trick, I just followed my own instructions from here. I don’t want to type a treatise on how to use command lines or rename files, but if you point out where clarification in those instructions is needed, I’ll do it.