SanDiegoRed Said:
"How do I disconnect MacBook from deleted iCloud account?: My MacBook Pro and iMac were stolen from my house, I subsequently deleted my iCloud account and opened a new one. By a miracle both computers were returned to me but they weren’t disconnected from iCloud so they’re trying to connect to the deleted iCloud account - how do I resolve this?"
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What to do:
A. Contact Apple Support:
Ask Apple Support if they can resolve this. If an option, you need to re-open the Account and then modify your credential immediately..
Note: Phone calls are taking a bit to go through at the moment, due to lots of calls. With the Coronavirus Pandemic, many are at home at the moment, with much time on their hands to contact Apple. So, just stay on the line, and you will get through :)
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B. Deauthorize All Option:
Once reactivated, try Deauthorize All. You can only Deauthorize All items once every 365 days. So, you may have to wait up to a year before you can perform this. Go Here: Authorize or Deauthorize your Computer for iTunes Store purchases - Apple Support
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C. Modify your Credentials:
Reactivated or not having so much suspicion, consider modifying your credentials, ASAP, starting with a new password.