Sealant is used to glue the panel on. Sikaflex, I believe. At least that's what the factory advised me to use in replacing mine.
In my case, there were two large roundish pancake-size globs on the underside, right and left, and in a few inches from the sides, towards the middle. I was easily able to get some give at the sides, but not enough to get a good stout tool well underneath. So I started working my way in as best I could, using a small pry bar, a large screwdriver, and a variety of other tools. The closer I got to those pancakes, the less give, and the harder it was to get any leverage or find space to slip any of the tools further underneath. It was was slow process. I eventually created enough space to slip a chisel in and under to hack through the large pancakes of sealant on the panel. In some areas, the backside of the wood on the panel tore free. Once I got about half of it off, I then had enough leverage to pretty much rip it all off, mostly tearing it free of the sealant at that point. To my surprise, I ended up getting it off in one piece. It might have gone faster if I had treated it more as a demo project and torn it off in slivers and pieces.