Remove the trap door, the (2) nylon washers  from the top and bottom of the trap door, and the (3) plastic riders  from the bottom of the trap door. Replace the washers  and the riders  if they are damaged.
Apply Mobil 460 grease to the nylon washers , plastic riders , and the trap door guide slot . Install the washers , riders , and the new trap door.
Install the bearing housing for the star assembly . Install the vertical axle nylon nut and flat washer  in the carriage assembly. Install the cover panel . Apply Mobil 460 grease the tool slots  on the star assembly.
Install the guide pin assembly .