HELP!! Port Forwarding w/o a router?

try putting in the address of your modem into a browser and see if it allows you to log on to the settings page. The easiest way to do this is to see what your IP address is and minus 1 from it e.g if your IP address is 192.168.0.2 then use 192.168.0.1. If you know the make and model of your modem then add that to the question and you may get a more detailed answer.