I have a Sharp Model R-508FS microwave. On the exterior of the door, it looks like the glue between the clear exterior protecting layer and the backing behind it has become discolored to a white and brown color. It looks like the microwave is "dirty" or rusted, when it is not, as this is sandwiched in between the oter skin and the next inner layer. I am looking for directions on how to get the door apart(seal??) to get this cleaned. Parts places have offered to sell me any parts I need for the door and say there are quite a few parts for the door so that it must come apart. How do I get it apart?