Removing you 2nd. A/C unit is not hard. Remove your power source, turn OFF breker, remove extension cord, whatever power source. Remove the Air Distribution Box ( ADB) for your unit, the part cool air flows from. Remove four (4) hex head long bolts that hold the unit to the camper and lower the sheet metal bracket from the ceiling. Disconnect the power source from the A/C unit. Tape the ends of the power source wiring to prevent future shock. Up on the roof remove the cover for the unit, this makes removal of the unit easier. Lift the A/C unit up and off the roof--careful, this unit weighs approximately 80#. Getting it off the roof will be the hardest part. I use an extension ladder and a helper. With one person on the ladder lay the unit on the ladder and slide it down. Remove the old A/C gasket, clean the area of the roof and place your new fan.
2015 FR Freedom Express 310BHDS pushing a 2014 GMC Sierra CC