Help me figure out how to remove the furnace on my Pop Up

Well it turns out I didn't have to remove those screws after all to get the furnace out, it was just really stuck but I finally got it out. It was a good thing too because there were wasps nests and all kinds of junk in it. The sail switch had a ton of dust and gunk on it, I cleaned everything really good, put it back in and it seems to be working good now. Thanks again.