TM 10-6640-215-13 4-19.  REMOVE/INSTALL COMPONENTS OF MAIN POWER PANEL - continued. c. Remove four mounting screws and withdraw defective circuit breaker. 2. Remove O1OA (A1CB2) Circuit Breaker.  See figure 4-8. a. Remove three mounting screws and withdraw circuit breaker to gain access to wires. b. Loosen all terminal screws, then tag and disconnect all wires. c. Remove defective 100a circuit breaker. NOTE All remaining circuit breakers are removed as follows. 3. Remove Circuit Breakers.  See figure 4-8. a. Remove one /mounting screw with keeper and withdraw defective circuit breaker to gain access to wire. b. Loosen one terminal screw, then tag and disconnect wire. c. Remove defective circuit breaker. 4. Remove Terminal Boards.  See figure 4-7 or 4-8. a. Disconnect all electrical leads and tag for reconnection.  If terminal board has busbar, retain for reuse. b. Remove terminal boards attaching screws, washers, and remove defective terminal board. 5. Remove Relay A 1 K 1.  See figure 4-8. Relay A1KI is a plug-in type relay.  It is removed by simply lifting the defective relay from its socket in the panelboard. 6. Remove Fuses and Fuseholders.  See figure 4-8. a. Remove fuse(s) from fuseholder clips by grasping fuse with fusepuller and pulling fuse free from holder. b. Remove fuseholder attaching screws, washers and lift fuseholder from panelboard. c. Desolder electrical leads from fuseholder, disconnect and tag for reconnection. INSTALLATION 1. Install Main (A1CB1) Circuit Breaker.  See figure 4-7. a. Align new circuit breaker in panelboard and fasten in place with four mounting screws. b. Reconnect electrical leads to circuit breaker. 4-41