The original Hasselblad eyepiece is a single piece: a mount plate bonded to a rubber part. Once the rubber is damaged, you have to replace the whole eyepiece. Our eyecup is 3D-printed in hard resin, with no rubber part.
This video shows how to replace the eyepiece on HV90X, HVD90X and HV90X-II viewfinders. You need a precision Phillips screwdriver that reaches 10 mm deep.