1) This is going to require you making changes to your registry. Open up the Run dialogue and type in regedit.
2) This will open up your Registry Editor. Before making changes, let's backup your current registry. Right click on Computer and click Export and choose where you'd like to backup your registry to.
3) Now navigate to the following location: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP-Tcp\PortNumber
4) Double click the registry setting to open it. Enter your new port you'd like to use, I am choosing 3379. Make sure that the Decimal combo box is selected. Once you press OK, restart your computer.
5) After the computer has restarted, open up the command prompt. Now type in Netstat -a and look to see that your new port is listed.
6) Now when you go to connect to this computer using the RDP client, make sure to enter in the port number after.