I have a 2008 Cougar Travel Trailer that has the "Polar Package". I suspect that the heating duct going to the Bedroom is crushed or has an obstruction. Very little heat comes out of it. Am I better off unbolting and dropping the Insulating "Belly Liner" or cutting out a piece of it to get at the Heating Ducts? If I cut it, how do I repair the seam? Thanks for the help!