Insert Disc 1, then press 666 at the main menu. The "censored" version of the movie will play, but will just be the opening and ending credits.
Hidden sequences
Insert Disc 1, then select the "Bonus Materials" option at the main menu. Highlight the Terror Firmer logo and press Enter.
Insert Disc 1, then enter "Commentary" screen. Select the "Watch movie with no sound" option to unlock a hidden sequence featuring Will Keenon and a information about a hidden page at the Troma website.
Insert Disc 2, then press 666 at the main menu to view a sequence featuring Lloyd Kaufman.