CmpLover - not sure that it is clear from above, so just in case...
You can access the back of the panel (and the screws mentioned above) by pulling the J-Steel partially open to a 30-45 degree angle and then craning your neck inside. Bring a flashlight, it can be dark in there. You can see the angle from X213_2015's link.
2011 Jayco X19H (purchased 2015)
2008 Jayco 1007 PUP (purchased new, traded for the X19)
2012 Chev Traverse LT with TP