You you have the XFI on your screen.
Top there is File, View, Communications, Logging, Window, Help
Click on Communications .. then you'll have Connect, below that Ping ECU, below that Start Server, below that Setup.
Click setup. Then youll see General, Com Port, Network.
Click Com Port and select Com Port 6
I cant baby step you further.
Maybe you need to download new software from FAST?? Dunno.