The best way to replace rollers on a sliding glass door is to remove the stationary glass door unit from its structural frame, unscrew the pertinent mechanisms, remove the old rollers, replace with new rollers and re-screw all the detached components. Finally, return the door to its original position.
The stiles of the stationary glass door unit must be unscrewed in order to access and take away the old rollers. Stiles are the side section of the aluminum frame. Totally detach the stile from the door with the help of a hammer and a chunk of wood. Only rails should stay on the sliding panel.
Locate the screw holes on the bottom rail, unscrew them, and pull out the base of the roller housing using a hook tool or needle-nosed pliers. Prior to installing the new rollers, modify them to the lowest position by adjusting the screw on the side of its body. This way, the glass door is not in a raised position. Insert the adjusted rollers into the side of the bottom rail, and screw them in place.
When all the new rollers are installed, lift the glass door unit, and slide the base rail back into its original location prior to detachment. Gradually replace stiles on all affected sides. Gently use the hammer and wood tandem to re-fit stiles back in place appropriately. Return the screws to the top and bottom of every stile. Make additional height adjustments for rollers, if necessary.