This glitch is for 4 players only.

When you open the stairs open the door to the speed cola machine too, somebody opens the door.

If you have crap guns kill yourself in front off the table and tell your teamate not to get you up.

As soon the round is over buy a Thomson gun and somebody stand under the grenade bag and the other people stay in that room where the sawed off double barreled shotgun is. Stay in that room and the zombies cant get you.

The man controls the glitch by ducking under the grenade bag. If he walks off the glitch wont work.