Currently Being ModeratedJan 3, 2013 10:06 AM (in response to robertfromdavis)
Any user with Admin privileges is an admin user. No changes need be made. If you wish to make an existing non-admin user to an admin user then open Users & Groups preferences. Click on the lock icon and authenticate. Select the account you want to change then check the box, "Allow user to administer this computer." To remove privileges from another admin user uncheck the same box.