[jmk]

I've done mine twice. Easiest with boat out of the water. Unscrew from the inside. Then from the outside use a razor blade to cut the silicone that seals the joint between inner and outer frames. Go back inside and slowly pry the frame away from the wall. Cutting the silicone all the way through is the key. Then push out the external frame. Once you have it all apart, it's pretty clear what to do next. Use something like 3M 4000UV for the external frame to hull joint, and clear Marine silicone between the frames.