Were is the switch in the castle in Mario 64 ds?

Go to the castle if you saved Mario Your able to do it! now if the sun carpet shines your able to do it! to make it shine to the carpet get more power stars! when your outside you walk in the castle. you will see it! stand on it. then press the X button on your ds.press down button to look up! Then you will be there with cap wings fly down to the giant piller u will see the red switch! Hop on it Then your done so your good to go!