how do i delete the admin user
Hi,
I am wanting sell my iMac so have deleted everything on the computer but I am still on there as admin...how do I delete the admin user? I have googled & it says select user & click minus sign bottom left of the window but the minus sign isn't highlighted to be able to click on...only the plus sign.
iMac 21.5″ 4K, macOS 10.13