To find these special secret hidden deleted scenes, go to the separate episode menus (press the + next to play) for the following episodes;

* "The Principal and the Pauper"
* "Treehouse of Horror VIII"
* "The Cartridge Family"
* "Realty Bites"
* "The Joy of Sect"
* "The Last Temptation of Krust"
* "Lisa the Simpson"
* "Simpson Tide"
* "Girly Edition"
* "Natural Born Kissers"

There should be a light on the speaker to the left of the screen. Press left as soon as you get to the extra menu. It should highlight the light. Press OK.