If you need to boot some users out of terminal services in Windows Server, try the following:
2) All Programs
3) Administrative Tools
4) Terminal Services Manager (this is also called tsadmin.exe)
5) Right click on the user you want to boot in the "Users" tab and click
6a) Disconnect - which may leave some of their applications running, I guess
6b) Log Off - which will log the user off, and should kill any processes they have running.
Of course you will need Administrator privileges to do this.
Since Windows limits you to 2 remote sessions, if someone has two disconnected sessions, you will not be able to log in without additional software, imagine that. So instead you could try using a different operating system that treats administrators like first class citizens.