non-jailbreak mods are easy, but they only work offline. make sure you are signed out before starting the game and don't sign back in until you have removed the mod. all it is is a savegame you need to get it resigned. You must login or register to view this content. have someone with xploder resign that to your psn profile and you have yourself some mods. (you'll figure it out once you start playing.)

which platform?