deauthorizing iMac Monterey OS
I have a new IMac and wish to clear my old iMac OS Monterey
iMac 24″, macOS 14.2
Follow Previous suggestion - First
One that is successfully done
Login to My Apple ID where your ALL Devices Using the Same Apple ID Account would be listed.
Find the recently device in the Device Sidebar
Click on it and choose to " Remove This Device "
This is just an Extra Step to insure it is totally removed from your Apple ID Account
