Step Two) Attach a plastic bag on the bottom of the coke bottle with a rubber band, make sure the only air escaping out of the coke bottle is through the top where coke would normally come out of.
Step Three) Either put a ratchet head, a bowl with rubber around it, or aluminium foil on the top to put the weed in.
Step Four) While the bag is still attached to the bottom of the bottle push the bag into the bottle.
Step Five) Light the weed and pull the bag out making sure there is suction and the smoke starts going into the bottle.
Step Six) Remove the bowl on the top and push the bag so the smoke goes deep into your lungs.