What I did on mine was to dremel out the arc'd part of the tank shelf. I had already glued the cardboard tube in place. I was able to take enough off of the back side of the shelf that the tank drops down just as it reaches the carboard tube. Then it is just a simple task to tilt the back of the tank upward and pull it out. I made it easier by making a duct tape handle on the rear portion of the tank. That way I have something to pull on. It works great.