I'm guessing you mean restarting your town. In the original Animal Crossing game, when the animal comes on the screen and asks you if you want to go into your town, select the "Not yet..." or "Before I go..." option. I'm not sure exactly how it's worded, but it's the option that isn't "Yes." The animal will then give you some options. Select "Other things" and then he'll give you some madami options. One of those options is "Start a new town" - This option will erase your current town and let you start a totally new game. If you want to keep your town but start a new one, just insert a new memory card into the Gamecube and then start up the game.
