depending on the glass, if it is soft glass(soda bottles beer bottles) type glas a torch will shatter it no prob, if it is pyrex type glass, glass cookwear, pipes, bubblers type glas make sure it is clean and u can heat the glass up till orange, stay in same spot and try to make sure all glass is warm b4 u start, then ust like a graphite rod to poke hole or glass rod to grab molten glass, and "pop" hole,... if u drill must use a diamond tip drill very expensive and run water over drill when drilling to control temperature of drill and glass good luck hope this helps