I got an e-mail about the replacement process, but was unable to return the reply. There were two questions, First, yes there may be some trimming necessary, I used a dremel with a sanding drum to clean this up. Second was, are the ports smaller, No, they are identical to the originals, however, ours were so bad, the new ones seem twice the size. Be sure to clean the hull where the frames fit so there is no chance of a leak. Good luck! John