You really only need to slit the throat. Unconsciousness takes about one second. If they're in a cone, they won't move far. They bleed better this way than cutting off the head, or at least they did for us. There's a great sticky at the top of the meat section with good pics of the whole process, including where to cut, which is at the top of the neck, under the "chin." A minute of wiggling, then you can take the head off at your leisure.