Heya Toons! PKH is in the zone! Presenting you the most likeley shortest page in this entire walkthrough!
As you arrive in the Gummi Hanger, Save and go up the stairs. In the garden, Kill the Hartiez and get the treasures. Follow the path into a door that leads you into a corridor. Go killin' Hartiez untill you get to the end of the hall. Because ol' PKH told ya! Talk to Minnie Mouse and go along with her through the hallway, Killin' Hartiez untill you reach the big bad door that was locked before. enter, and go through the chamber. Don't atack the Hartiez! They regenerate! Use Minnie's reaction command to make the Hartiez leave. Get to the end of the hall, and down the stairs, and after the cutscenes up to Hollow Bastion, then up to the Hall of the Cornerstone save point, and up to the door.
Or... a Mickey Mouse cartoon?!