put a hole in the cap. Put a bowl in there, preferably glass. Put it in a pitcher full of water (Tea pitcher is usually perfect size, if not a bucket will do). Oh yea, cut the bottom off the 2l too
I\'ll quote something I put in another thread. The link will give you 2 other ways. Some isn\'t applicable to your question so just ignore that. Also you can search the forums to find other ideas. http://forum.grasscity.com/search.php?
make a gravity bong. take any large bucket (example: an emptied ice cream bucket). take the 2 liter. cut off the bottom part. stick the 2 liter in the bucket and remember how tall the 2 liter sits in it. then pour water into the bucket till it\'s about 2 inches beneath the neck of the 2 liter. the 2 liter should be sitting in the water. put a bowl on top where the cap used to go. light the bowl and slowly pull the 2 liter up. watch the smoke fill up inside the bottle between the bowl and the water. after it\'s full, push the 2 liter to the bottom as you pull the bowl off and suck all that smoke in.
fuck the bottle. You want somthing good to smoke outa that will get you faded? Ever heard of a sobe? Its a cross between a grav and a waterfall bong. Basically @ the bottom of the sobe bottle theres a indent--punch a small hole in there (the glass is slightly thiner). This will be your carb. Then for the bowl piece--well take the lid of the sobe bottle, take the plastic crap off on the other side of the lid (theres some plastic shit-probally used for helping with sealing, I just toched the plastic a little bit until it serpated from the underside of the lid and tore it off--rather easy) Then punch a whole in the lid for your bowl piece. The bowl piece can consit of anything, hell you could punch holes in the top of the lid if you want (sorta like you would for a pop-can pipe) Anyhow heres the smoking part now: Put your finger on the carb (at the bottom of the bottle-the little hole you punched in the glass) and fill the bottle up with water all the way up to the top. Put the lid on the sobe bottle, put yoru bud in yoru bowl piece (which is the lid or w/e you decided to do for the bowl piece--I used a harware nut) Light the bud while slowly draining the water out of the \"carb\" on the bottom of the bottle--not to fast, nice n\' slow while keeping the heat on the bowl until the whole bowl is gone. The bottle will be filled with smoke, heres the tricky LEAVE A LITTLE BIT OF WATER IN. So before all the waters gone, and the whole bowl of pot has been lighted and the smoke is all in the sobe bottle proceed to put your finger on the carb. Then take off the lid, put your mouth to the sobe bottle, and inhale while opening up the carb (take your finger off the carb) the air will come into the sobe bottle, and cycle through the water (bubbling it), and circulate the smoke. This hits rough and will make you choke, but youll get high as fuck. Its a great way to conserve pot as well. And a sobe bottle is nice n\' portable as well. The bowl piece is the crucial part though. For my bowl piece I just used a hardware nut, and a bunch of electical tape to hole it onto the sobe bottle lid. But ya--the sobe is perfect. Its portable, and easy to use and will get you faded. Man I used my last one so much I resinated the hell out of the sobe bottle, it was becoming yellow! lol Heres a little crappy diagram of what it should all look like: