You will have to brake the 2 water connections on the back of the heater. It may be easier to just cut the piping where you can reach and splice after the new install. The trailer body was installed after the heater was and thus you may have to cut the shell a bit to get the heater out to allow for the insulation to pass through the opening.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles