there was a really good post with instructions, but i'll try to explain.

get a bottle or really any container with a screw on top. on the top, cut a hole and put in a bowl(wrench socket or whatever). on the bottom of the bowl(coming off of the bottom of the cap) put in piping so that when you put the cap on the container, the pipe amost touches the bottom. on the container, put a hole near the top, and another hole with a tube(for mouthpeice) coming out of the hole.

so you see, you fill it with water, and light up the bowl and it bubbles up from the water, and when you release the carb it no longer bubbles and you suck out of the chamber.