How to erase the SSD in my older iMac
iMac Line (2012 and Later)
What are your plans for the older iMac?
If you want to erase, reinstall and keep it for yourself,
see > Use Disk Utility to erase an Intel-based Mac - Apple Support
and > How to reinstall macOS - Apple Support
If you are selling it, giving it away, trading it in or recycling it,
see > What to do before you sell, give away, or trade in your Mac - Apple Support
Thanks den.thed and Mal-S for your solution. After rummaging around the web I came to the same methodology. Somehow I missed the instructions for what to do what is different for an Apple M1 chip. I hadn't had the need to erase the the SSD chip in an M1 equipped Mac. The computer is to be disposed somewhere. I was posed the question for its owner, who is a total novice and didn't know about Disk Utility! Thanks all. Once again the Community has answered my questions speedily and correctly.
Squidman
Deleted comment
You're welcome.
Erase the SSD
