Give a user administrator privileges on a Mac. This can be done while signed in to any account as long as the user has previously signed in.
macOS
If your admin credentials do not work in Step 4, make sure the computer has access to the UM network (MWireless, Ethernet on-campus, VPN off-campus). Also check in Izzy to see if the UM Support account is active. Otherwise, look at the list of accounts in Users & Groups to identify which one is already listed as an Admin, and search for those credentials.
Read our "Making user account administrator on Mac from terminal" article for steps on how to make a user admin using terminal and a remote connection.