2 cinder blocks (or anything fairly tall and big enough to support the wood)
anything over a foot long of wood (not too thick)
the 2 liter
a cork big enough to fit in the neck of the 2 liter without leaking water through
bicycle pump with the needle
A drill or a local hardware store that can drill a big enough hole to fit neck of the 2 liter through.
Put the two cinder blocks far enough away from each other to comfortly place the wood on top of. Then place wood on top.
Drill a hole in the middle of the wood, large enough to fit the neck of the bottle through. My local hardware store was able to do this for me.
Fill the 2 liter with somewhere around 1/3 to 1/2 of water.
Jam the cork in the neck, far enough in so the cork isn't sticking too far out side the bottle, but far enough so you can pull it back out if a problem arises.
Place neck of the 2 liter through the hole of the wood, make sure it stays balanced.
Slide the bicycle pump needle through the middle of the cork so you can pump air into the bottle.
Pump air into the bottle until the bottle blasts off. Make sure your not too close to the bottle and make sure it is standing straight up. It may be necessary to use another piece a wood to balance it as seen in my video.
Enjoy! I hope these steps worked for you, and if they didn't, feel free to tell me.