john vrtiak, usually we like to refer questions about microwaves on here. Those things pack a lot of oomph and are not a good DIY'er (unless experienced) project. Anyhow, the fuse change seems to be straight forward enough, it is behind the control panel.
Remove 2 screws from front vent cover and removed vent cover
Remove one screw from top of display
Gently push display panel up about 1/4 inch and tilt the top toward the front.
Disconnect 3 thin gauge Molex connectors
Disconnect 1 heavy gauge connector
Remove screw from grounding wire at bottom of display circuit board
Remove display panel completely
Remove grill from above display area
To the left is a 2 x2 inch square board
Coil, capacitor and fuse block
Match fuse rating and replace
Number 47 on the diagram is the fuse. Hope this helps, good luck.