I can assure you that's how those panels come off. I posted pics on this thread a few years back. I used a flat metal pry bar, and protected the trim below as you mentioned. I needed to this when I mounted the flat screen TV up there to make sure i screwed into the studs behind there.
if I remember correctly I ran it all the way over to starboard side and found a wire run, and came up through there. Quite a bit of room once I removed the seat back and exposed the A/C unit.
Agree with the others, however if you magnify the first pic you can clearly see the deck hardware/screws are loose, no evidence of caulk, and there are multiple cracks above the anomalies/blisters where moisture could have entered over time.
I haven't used them yet. I bought them from of @ocgrant as he ordered too many. Once I removed my door I was able to clean my existing glides and tracks, and still have the new ones in my stock for future use.