TM 9-2320-209-20-3-4 23-26. VAN BODY PERSONNEL HEATER DUCT REMOVAL AND REPLACEMENT (TRUCKS M109A2 and M109A3). TOOLS: Open end wrench set, pn GGG-W-636 SUPPLIES: None PERSONNEL: One EQUIPMENT CONDITION: Truck parked, engine off, handbrake set. a. Removal. FRAME 1 1. Using wrenches, loosen two capscrews (1). 2. Using wrench, unscrew and take out capscrew (2). Spread open and take off strap (3). 3. Slide duct (4) off heater adapter (5) and adapter (6). END OF TASK 23-93