Before you attempt to remove it, I would ensure that replacements continue to be available through Beneteau spare parts. If you break it, you will have fabricate a replacement, if Beneteau does supply them any more.. The lens is cast acrylic with a beveled edge and painted perimeter (no frame). I would try a multi/oscillating tool with a scraper blade / non cutting blade from inside cabin or exterior surface.....where ever you can achieve the best access. Can also supplement with LOW heat to soften the adhesive/sealant. If you can lift one corner, you can insert a windshield removal wire cutter to cut through the remaining sealant.
A quick temporary fix is to use Captain Tolleys creeping crack cure around the perimeter of the lens, where there appears to be an opening between the lens & topsides. I used it on a leaking fixed deck lens and it worked OK for a few months; should work better on your application. Please keep us updated; I have four that are still sealed.