This micro came with a home we purchased. It is installed in a cabinet over a built-in Frigidaire oven with a trim kit, and overall it is a very good product.  The inside of the door, however, is spotted and stained. The previous owners told me the micro came with a piece of plastic film over the glass inside the door. They removed it, and from then on it has been impossible to clean the inside glass. I just can't stand looking at it!  Is there someway to clean the glass? Can the door be replaced? If I have to replace the micro, I won't buy another one like this.