Locked out of MacBook Pro after changing iCloud email
Hello!
My iCloud email/Apple ID was an account I no longer use (and have deactivated), so I changed it to my current email address. It worked on my iPhone and iPad. So far, so good. But my MacBook Pro does not seem to have changed the ID email - and now I'm locked out of my MacBook.
I'm currently trying to temporarily re-activate my old email account, in order to try changing it all back to the previous iCloud setting so that I can (hopefully) log into my MacBook and then go through the process of changing everything/every device to my new email again... but just my luck, Yahoo is having technical problems and I haven't yet been able to re-activate.
Is there any other feasible way to be able to access my MacBook so that I can change the account information? Any help would be greatly appreciated!