On our Roo, our front bunk got wet after about 5 seasons. I decided to replace the wood instead of the entire panel. I did not have to remove the panel. Our Roo did not use poles to support the bed, ours had cables that were attached to the trailer body.
I removed all the hardware from the bunk end except the piano hinge. Once the hardware was removed, removing the wood was pretty straight forward. I removed all the staples and then used a putty knife to separate the wood from the foam insulation. The wood was wet when I removed it, which probably made it easier to remove. I went with 1/4" oak plywood. I used a spray adhesive designed for foam to adhere the plywood to the foam and then put all the hardware back on.
I let the bunk end completely dry for a few days before attaching the plywood and putting it back together. I took me, by myself, about 4 hours to tear down, replace wood and put back together. I also used Liquid Nails to adhere the plywood to the aluminum frame.
-Michael
