Hey guys, this glitch is really easy to do, it's just that you need to get the Paralyzer from the box. Come to where I do and shoot the gun while looking down and jump and you will start flying. Then while in the air go forward where I'm at and crouch. All zombies will pile up in front of you and you also have an unlimited ammo source. Your teammates can also get in the back of the barn and take turns killing zombies. Enjoy!