Instructions
Open the door to the third floor of the castle. This door requires 50 stars to open and leads to the room that holds Tick Tock Clock and Rainbow Ride.
Climb onto the staircase that leads to the final door. Walk up to the second step and face the third step, slightly angled to the left. Stand close to the corner between the wall and step.
Charge a forward run by pressing "Up" on the D-pad and holding the "Y" button.
Release "Y" to start running and immediately perform a slide kick by holding "R" and hitting the "A" button. Hold "Right" on the D-pad as you slide. If this is performed correctly, you will be flung into the air, passing through the ceiling and into the room containing the entrance to the final level.