This walkthrough will get you through the game the quickest way possible, but not necessarily the best way:

Wait through the opening scene, until you are in the Walk-In Freezer.
Push the plate three times.
In the next room, go west three times.
Wait 21 times.
Pull the IV three times.
Push the button.
Wait twice.
Eat the cracker.
Drink the milk.
Enter the door.
Examine the parchment, and you’re done!

Easy peasy.  But definitely not the BEST way to complete the game.  Unless you’re into the whole brevity thing.