To remove the roller from this patio door, you must first remove that bottom door rail. Your best bet would be to lay the door on a strong work table or set of saw horses. With the door laying securely on a stable surface, remove the frame screw at each end of the bottom rail of the door. The other screw you speak of is the adjustment screw which will stay with the roller housing. With the frame screws removed, try to tap off the bottom rail using a block of wood and a hammer. In most cases the bottom rail can be removed. Be careful not to damage the glass or frame of the door. If you are not confident about this project you might want to get the help of a professional.