Check the thread on the maint and mechanical "leaky windows on 27" there are mant ideas on what to do. I posted my thoughts as a reply on the above listed thread. Also look under the 27 owners manuel under specs and documents. The process is simple and takes a couple of hours to remove clean and install the ports. bed all surfaces glass to rubber rubber to frame and frame to boat use closed cell foam. Tools needed a + and - tip screwdrivers, a scraper, solvent and patience.