I planed on repairing the cabinet with it up, looked easy till I got my head in there and then tried to get my arms and hands in, after about 3 hours, I gave up on that idea and realized that to do a proper repair the cabinet had to come out. Was so frustrated because I discover that there is some water damage at the top of the wall door side and I don't know where it is coming from, point is I didn't take any pics of the cabinet removal, as soon as I get settled down, I will take pics of the cabinet and explain how to remove.
On another note I would not try to screw up to the top roof panel as I don't think it is very thick and a slight misjudgement in screw length and it would go thru the roof. I am guessing at 3/8 s panel as I just put a solar panel on the trailer, it originally had one or they marked the holes and the wire hole and then caulked them in. I opened the wire hole up some and the panel wasn't very thick, could have measured it but didn't think too.
Anyway pics coming. Here they are. First pic is of the end of the cabinet, yours is covered with cloth. Second pic is of the inside,showing the back top panel of the hollow bottom.
3rd pic is showing the panel removed, I removed the staples close to the wall and then pulled the panel up, wall side and the staples pulled right out of the front. Last pic shows one the screws that have to be removed from the wall, they are inside the hollow bottom. The screws that are screwed to the roof are inside the top of the doors just open to see.
If I can help more just ask.
(215TL) - 1995 21' TowLite
(2209T) - 2009 22' TowLite
99 Ford Explorer 4DR 4X4