TM 9-2320-209-20-3-3 c. Replacement. 1. Put back rest (1) in position. 2. Line up mounting holes in bracket (2) and back rest (1). Using phillips screwdriver, screw in and tighten two screws (3). 3. Put wear plate (4) between back rest (1) and brackets (5). Line up mounting holes. Using screwdriver, screw in and tighten four screws and lockwashers (6). GO TO FRAME 2 18-24