Back up any important files to an external drive or cloud storage
Sign out of iCloud, iMessage, and FaceTime
Open System Settings or System Preferences
Go to...
Back up any important files
Sign out of iCloud
Sign out of Messages
Sign out of Music, TV, and other Apple services
Restart the iMac and enter macOS...
If you know the current password, go to Apple menu > System Settings > Users & Groups
Select your user account
Click Change Password
Enter the current...
Back up your data with Time Machine or another backup method
Sign out of iCloud, Messages, and any other Apple services
Open System Settings or System...
Shut down the iMac and unplug it
Disconnect the keyboard
Turn the keyboard upside down and gently shake out loose debris
Use compressed air in short bursts...
Back up any important data
Sign out of iCloud
Sign out of iMessage and FaceTime
Open System Settings
Go to General
Click Transfer or Reset
Click Erase All Content and...
Back up any important files
Sign out of iCloud
Sign out of iMessage
Sign out of FaceTime
Open System Settings or System Preferences
Go to General
Select Transfer or Reset
Choose...
Back up your data
Sign out of iCloud, iMessage, and FaceTime
Restart the iMac
On Intel iMac: press and hold Command + R during startup
On Apple silicon...