No they didn't mask off areas. Removing from the boat is easy. Taking it apart was a pain, they silicone the glass into the frame. On reassembly the glass fit fine, use a spray bottle of soapy water and spray the crap out of the rubber before assembling so you can move it into place better. Also a soft rubber mallet. The hardest part was getting the dowel into the hinge. Lots of lithium grease or any lube helps. In hindsight a tiny round file may have helped. Also drilling out the rivets proved a little challenging.
All worth it in the end.