Try this : build a cradle out of plywood with three sides , put the AC on it with the no side facing up on a ladder laid at an angle from ground to top of camper.The ladder need to be long enough give a not too steep angle, the top rung of the ladder has to be higher than the roof top at least the lenght of the cradder. Hook a 12 volts winch to the top rung of the ladder , hook the wire to the top of cradder and winch it up. if you can find a remote control winch (real cheap at Hardboard Freight ) you can do it alone. Good winching.
Joe
