How,exactly do I put in the cheat codes for the Wii Transformers: Revenge of the Fallen game?

I keep looking at a bunch of game sites and I can find cheat codes but I don't get an exact answer as to HOW to actually put the codes in. The best I've gotten is that I go to the Campaign but that was it. What do I DO once I get there???? Please someone if at all possible could you break it down elementary style for me! My son is buggin' me! LOL!! Thanks for any help out there!How,exactly do I put in the cheat codes for the Wii Transformers: Revenge of the Fallen game?just dont play it