We have had a La Luna door for ages, and realised the flap was really discoloured and needed a change. We ordered a replacement flap. It arrived very quickly (even to Darwin!).
I watched a support video, which make the change look really easy...like a 15min job. Word to the wise...if you haven't changed the flap for years, or you live in a very hot climate, the plastic can melt and fuse to the door itself. If this happens it becomes more like a 2-hour job, which requires you to disassemble most ...