So what do you do if your oldish Mac refuses to change the email address for your Apple ID?
How do you get an old Mac to realise that you have changed your email address and therefore Apple ID? It just doesn't recognise it, and all attempts to change it following various forum instructions have failed!
Done it successfully on iPhone and iPad, but old Mac won't play ball: keeps prompting me to sign in with the old email address, which doesn't work!!
Earlier Mac models