Hi yo. Well, there are generally two plugins that you can use to hack SOCOM: FTB2. They are called CWCheat and NitePr. They are essentially GameSharks or ActionReplays. Install it, put the codes you want, enable those codes. Voila. So yeah, just Google: "CWCheat for 3.80 M33" or "NitePr for 3.80 M33". Then, install it and find FTB2 codes and put them in. Console Discussions has some tutorials on how to do it.

P.S. Haven't been on in like 500 years so don't criticize me for being a noob, it's just that I am bit rusty.