I just ran into exactly the same problem. It breaks down like this: Unlike all the microwaves I’ve seen in recent history, (the one I was fighting with was vintage 1985) this microwave does NOT hang from the four bolts in the bottom of the cabinet above, and off of a mounting plate in the back. Instead, those four bolts (as well as the two in the back that you see when you remove the top front grille) support a complete wrap-around metal housing. The microwave actually sits inside this sheetmetal box and slides out after you remove all the appropriate screws. This includes the two screws facing you at the top, when you remove the vent cover above the door. Also, the seven or so screws on the bottom need to be removed to gain access to the bulb. Once the bottom plate is removed, take out the bulb and remove the three screws on the electrical access box and disconnect both plugs inside. At this point, two people should be able to pull the microwave body straight out of the housing. Basically, its a box inside a box. If it won’t go, check for more screws. They are all little guys, about 1/2 inch phillips drive sheet metal screws. Good luck.
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