Ok first the vertical bolts with jam nuts should be tight against up against the flange on the slide box and the jam nuts tightened. Now to bring the top inside out against the seal you need to loosen the two bolts you see in the bottom picture and lower that portion a little using the vertical bolt I mentioned. Only make small adjustments and then recheck. Let the form know how it goes. The day before put some PB Blaster where the flanges meet.
Jake my sidekick (yellow Lab)
2017 RAM 2500 CC 4X4 Cummins Diesel
2016 Flagstaff 26 FKWS
AF&AM & El Korah Shrine of Idaho