FC6 - DISABLE root login at Console/GUI

[thsk]

Greetings all...!!!

I would like to disable root access at the console. What is the best way to do this on a FC6 box?

This is an old machine running Fedora Core 6. Its purpose is to serve dhcp and runs great without any performance issues. I am not interested in doing an OS upgrade at this time because the hardware is ancient. I grabbed the box to serve some private networks after it had been abandoned by another department.

BTW: I can't change the root password because of management issues. I just want to compel my colleagues to log-in through ssh! I have already locked down root access in ssh.

Many thanks!
-Bob