That, sir, sounds like fun. Reminds me of a Steven Segal film, though. And he sucks. :<:O! A thread about what I love best, awesome.
Easy way: Hold someone in a headlock to where your back is touching their shoulder and you are reaching behind you to keep them inclosed in the headlock. Slowly, bring your hand down in a fist towards your waist. Whilst still keeping the victim in a headlock, twist the fist and the waist (at the same time) together and pull it as far as you can out in front of you. If done correctly, this will rip the spine from the back of the skull, instantly killing the person in the headlock. It'll also keep everything together so it looks like they just got knocked out.
Too lazy to list the 5 billion other ways I know how to kill someone, meh. D: