请教大神，这段英语是什么么意思？不要用机器翻译。

请教大神，这段英语是什么么意思？不要用机器翻译。
机器翻译我自己也能弄，所以不要机器翻译，如果你看不懂，就不要回答，回答的话会误导我、
Cut the top off a 2 liter soda bottle and place a 16 oz soda bottle with holes in its bottom in it, use a butane or propane torch to heat the top of the 2 liter until the plastic shrinks down around the top of the 2 liter, this will hold it in place and still allow gas to escape.