The most difficult part of pulling the furnace out of my Excella 500 was drilling out 8 rivets and unscrewing lower framework holding the tambour which hid the furnace from view. After getting that out of the way, it was a simple unscrewing of the main gas line (copper), disconnecting the electrical connection on the side, unscrewing the furnace exhause cover plate on the outside of the trailer and then pulling the unit from under the kitchen cabinet. On the install, I used putty tape around the furnace exit for a secure seal from water access and there is a rope washer that fits the exhaust plate from the inside. It was a simple job other than the framework. The access to your furnace may be easier than mine, let's hope.
'01 2500hd ext. cab, 8.1 litre gas, 5 sp. Allison auto
3.73 rear end
Mag-Hytec rear diff cover
Amsoil Dual by-pass oil filtration system
Amsoil synthetics all around
265 watt AM Solar, Inc. system