Uninstall an old iMac to recycle
How do I wipe clean an old iMac so I can give it away?
How do I wipe clean an old iMac so I can give it away?
Follow the directions, at > https://support.apple.com/en-us/HT201065
(note: the erase your hard drive link in step #7)
Follow the directions, at > https://support.apple.com/en-us/HT201065
(note: the erase your hard drive link in step #7)
Here are specific instructions: What to do before you sell, give away, or trade in your Mac - Apple Support
Uninstall an old iMac to recycle