How can I update a iOS system on a 2009 iMac?
It is currently running on Sierra iOS. I need to upgrade in order to delete the computer and recycle.
It is currently running on Sierra iOS. I need to upgrade in order to delete the computer and recycle.
You do not need to update the macOS.
You do need to Erase your Mac's before recycling.
see > What to do before you sell, give away, trade in, or recycle your Mac - Apple Support
How can I update a iOS system on a 2009 iMac?