How do you knock someone out without hitting their head?

It is not possible. The movies and TV have made people think that you can get conked on the head, fall down unconscious, and jump back up in a few minutes with no problems, but that's just wrong. If you are hit hard enough to lose consciousness, your brain gets bruised. If you don't hit the head exactly right, you could even crack or break the skull. The person will wake up with a severe headache at the very least, and most likely will have a concussion, memory loss, and maybe permanent damage. Don't try this one at home!