Wyctoronto, can I ask why you're looking to have these replaced? are they leaking, crazed? I attempted to remove the plastic trim ring on the starboard side forward port but stopped as it was held in tight and I was worried that it would break. if it was me and I was going to replace the acrylic I would just go ahead and buy all new opening lewmar ports, that would be a nice upgrade and you wouldn't have to worry about breaking anything. Future lense replacement would be a lot easier as well .