Welcome to the forum. You will find much helpful info here.
I have replaced the heater core on my Journey and the front cap had to be disconnected and tilted forward. Hang on and I am sure some of the owners of Adventurer's and similar coaches will respond.
It would be helpful to tell us which chassis you have...Ford or Workhorse. Not sure that will make a difference but perhaps so.
Also, you can always contact the folks in service at Winnebago with your question. Their email is
or@winnebagoind.com