I’ve had a computer and a laptop for a long time, but just recently got a second computer for the kids to use. I wanted to be able to connect to it remotely, but needed to know how to change the listening port. Normally the RDP port is 3389. A quick search pulled up this Microsoft support document.
http://support.microsoft.com/kb/306759
There is a Microsoft Fix-It option, or the instructions are there to do it manually in the registry.