I recently changed the belt on our 42QD and below is the write up that I posted.
Yes and it is kinda of a PITA. You cannot do it from the bottom only you also need access from the top. On my unit the 42QD I removed the divider of the bathroom sink between the cabinet doors then the cabinet bottom, 2 pieces, below that remove the pine wood frame that the cabinet bottom screws to. The frame is to big to get out of the cabinet so I just lifted it up and out of the way so I could then remove the metal access hatch to get to the rear of the engine.
Get under the engine and take the pressure off of the tensioner so you can slip the belt off of the pulleys then go back on top. You will need to remove a small nut and bolt from a bracket that spans from the engine to the outer fan hub and unplug the wire harness it supports so you can remove the belt. Put the new belt on in reverse order. I did most of the work myself except putting the new belt back on since the new belt is smaller and hasnít been stretched out yet. I needed help with the tensioner below so I could reach down through the access hatch and slip the belt onto the idler pulley after it has been placed over all the other pulleys.
The first photo shows the bathroom cabinet with the pine frame in place and the second is looking down through the engine access hatch showing the bracket that you have to take apart.
I can say that now that I have done it I could do it much quicker if I ever needed to.
2013 Itasca Ellipse 42QD - Tow Vehicle 2017 GMC Acadia
2012 Forest River Lexington 265DS GTS