Adding and Removing Domain Users from the Local Administrators Group on Remote Computers Using C # and WMI

I am working on a small utility that will be used to manage domain users who are in the local administrators group on this remote computer. I want to be able to enter the computer name and username from user input (text fields) and add or remove a user from the administrator group on this computer, depending on which switch is selected (add or remove). I looked around and could not find anything about how to do this using WMI and C #. Any help is appreciated. Thank!