Sliding glass patio doors use two sets of wheels secured in the base of the door and running through a track on the base of the door frame. If the wheels are damaged, the door can no longer move smoothly, often jumping the track or getting stuck. Replacing the wheels can solve the problem, but requires you to remove the door from the frame. The process is simple, but because of the size of the door, you'll need a helper to ensure safety.
Search for the small roller wheel adjustment screw near the roller on the side or bottom of the door in the frame. Use a Phillips-head screwdriver to turn the adjustment screw counterclockwise to raise the rollers higher into the patio glass frame. The increased roller height will make it easier to pull the sliding glass patio door from the frame for wheel replacement. Raise both roller wheels in the door as far upward as possible.
Center the door within the patio door frame. With a helper's aid, lift the door in the frame until the raised wheels at the bottom of the door clear the bottom track. Pull the bottom of the door toward you at an angle, slightly lowering the top of the door. Watch the top of the glass door as it clears the track at the top of the frame. Remove the door entirely once the top clears and lower it to a flat surface where you can access the wheels at the bottom of the door freely.
Remove the mounting screw holding each set of wheels in place, using the Phillips-head screwdriver. You'll locate the screws either at the side of the frame or along the bottom. Place a flathead screwdriver between the wheel unit and the frame and pry the unit from the wheel well in the frame with the screwdriver after removing the securing screw. Clean dirt or debris from the wheel wells with a nylon brush.
Adjust the new rollers to sit in their highest position, using the Phillips-head screwdriver and the roller wheel adjustment screws. Slide the new wheels into the wheel wells, placing them into the same positions as the wheels you just removed. Secure the new wheels in place with the mounting screws.
Set the glass door back into the frame, with the aid of your helper, by sliding the top of the door into the track along the top of the frame with the door angled inward toward your feet. Lift upward with the top in place to move the bottom of the door containing the wheels over the track in the bottom of the frame. Gently release the door into place and use the adjustment screw to set the wheel height so that the glass door slides effortlessly through the track to open and close.
Wear a pair of work gloves when moving the door in case of breakage.