Click Windows + R to open the Run dialog box. Type Regedit to open the registry editor.

Navigate to:

 HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp

Look for 

 Port Number

Click Edit > Modify.

Enter the new port number and click OK.

Close the registry.

Restart your computer.

Check if you can connect to the remote computer.