So can anyone explain how to forward the ports? It would be much appreciated.
I just now got this all sorted out for myself, so now I can offer help. =)
Go into your Router Setup page (Type in the IP 192.168.1.1 in your web browser of choice. The default password is "admin", no username). Go to "Advanced" and then the "Forwarding" tab.
For MSN Messenger, enter the information like it's shown below (Note that I have the latest firmware update, your settings may look slightly different, but all the same options are still there):
Note that your internal (LAN) IP may be different from mine. You can check your IP by going into the command prompt ("fake" DOS) and typing cmd <enter> then ipconfig <enter>. It will display your LAN IP. Enter the last 3 digits where "100" appears in the pic above. If that does not work for you, than try using 1863 in place of 13984.