Rebedding leaking lexan ports
There is a product called "release" which, when applied to old caulk, tends to help it come off. Appears to be at least somewhat effective on silicone and polysulfide. There is another liquid for polyurethanes (5200 and 4200), called "debond". Available in WM. Not perfect, but it does help. OTOH, when I replaced (not "rebedded", but "replaced") my plastic portlights, I literally cut them in pieces and cut them out of the fiberglass with a reciprocating saw--would have been 10 years getting them out any other way--but of course the plastic portlights were then just small pieces and not reusable.