TM 9-2320-209-20-3-1 b. Replacement. Soldier A 1. Put buzzer (1) against firewall with connector (2) pointing down. Line up three mounting holes in buzzer (1) with holes in firewall. Soldier B 2. Put three screws (3) through holes in firewall and hold with 7/16-inch wrench. Soldier A 3. Using 7/16-inch wrench, screw on three safety nuts (4). Plug connector (2) into buzzer (1). NOTE Follow-on Maintenance Action Required: Check operation of buzzer. Refer to TM 9-2320-209-10. END OF TASK 7-189