so i'm gonna make my second homemade bong out of a Jolt cola can ( http://www.bevnet.com/images/reviews/jolt/jolt-cola.jpg ). How should I go about cutting a hole in the side of it (where the O is) for a slide? i really want to make it my friend and i thought of the idea when i bought one, the opening is perfect, IMO. thanks in advance guys, peace bros