You have catch dogs, like pit bulls, holding onto the hog. You have to get to them quick, otherwise the dogs can get hurt. Once you get there, you place the knife behind the shoulder and give it a push. Some people will go through the trouble of flipping the hog or holding the back legs up, but I've never found that necessary. Keep pushing until you hit the heart. It's all pretty quick, just stay away from the sharp end of the hog .