Usually one screw is used hold the blower,burner,gas valve and board assy. in the can that the ducting tube are connected. The gas line and wires are to be disconnected first. Bryant RV is a great resource. Mud dobbers put mud on my sail switch, my blower fan ( out of balance) and over the jet hole, before I installed aftermarket screens. If a board is needed, use a Dinasour aftermarket board.
2001 dodge 2500 auto, with billet Mojave Green torque converter with 2nd gear lockup mod, raptor 100 fuel transfer pump and gauges. RV75 injectors
94 Alpenlite 27sl with many mods.