When the rollers of your sliding glass door break, it becomes very difficult to use the door. When you want to repair your old sliding door, make sure you have someone to help you in moving the door because they are usually very heavy. Connect the roller screw with a screwdriver and move the door back and forth, then lift the door and pull the bottom side inwards. Locate the frame screw which is just above the roller adjustment hole, and remove it entirely using a big Philips screwdriver. Now take out the older rollers and see if they are repairable or need replacement.