1st Glitch Tutorial :
1. go to the fire well area near spawn
2. make sure to dolphin dive across the well on the small rigid broken plank shown.
3. if done correctly the zombies will all pile up and you can hop out whenever.
2nd Glitch Tutorial :
1. go to the area with weapon damage perk behind spawn.
2. Line up with the plank until you can see inside it and down yourself.
3. turn around and push back into the wall and have someone revive you