How do you get waluigi in sm 64 ds

well when you get all stars and all minigames you go out the castle go in the cannon and blast to the giant picture of peach and you'll see a secret room go in there and ask rosilina to give you WALUIGI for a star and you go get (Mario luigi and wairo) to lose all their hats Mario loses his cap by getting it takken by klepto luigi loses his cap by a ukiki and wario loses his cap by getting it blown off by a snowman then (go back an be Yoshi) then you'll see a ? box hit it and you'll get a WALUIGI cap have fun being WALUIGI