Stephen, you better take into consideration, if the glass cylinder is under any pressure once you loosen the top bolts you stand a chance of the glass cylinder cracking. I have alot of friends who found this out the hard way. One of my friends had removed the glass cylinder and it was sitting on the floor for a week, when he heard it crack. I guess something to do with expansion. I am only telling you this so you will be careful. Take care and I hope it turns out alright for you. Hugh