Hacking mw2 on consoles is somewhat complicated and requires some knowledge in computers, and certainly not worthy, keep in mind that if caught(usualy takes 1 to 2 days) your console will be banned,...
Well you can't so ha! hackers like you are appaling! just play the game properly! Btw. Mod xbox's are just a waste of money so don't even think that's going to help you either!
If your on xbox360, your need to jtag your xbox, if your on ps3, your need to jailbreak your ps3, for more information search on youtube above the two hacking term i used (jtag xbox360 and ps3...