Basically, you go to a site that has codes (www.cmgsccc.com has a large database of em) and you basically type them into the gameshark.
Or you could just play the game as it was intended to be played, instead of paying for cheating devices. Indeed
If you’ve already made a mistake, then just start the game over again and play through it first. Then once you’ve won the game, you can play it again with game shark.
In some games, in particular my current fav, Dynasty Warriors 4 Xtreme Legends, the requirements for getting the Level 11 weapons is absurd. They can be done, but are extremely hard, henceforth, the weapons are extremely worth it when you get them. I admit, I have considered buying an action replay and using it to get all of those weapons, but I won’t. I want to get the weapons the way it was intended, by playing the game (and going nuts when I fail… repeatedly.) not the easy way.