Why a tenant would remove and discard the grease filters without replacing them is beyond me! But, I removed the filters from the package and slid them into place. Two minutes tops. I would like to add that I ordered these on Thursday afternoon, and I had them on Saturday; awesome customer service!
I ordered a new coupler and dropped it into the center hole, jiggled it until it fell into place, put the turntable back on the track, and voila, fixed! It was ridiculously easy.
Unplugged Microwave, Removed vent cover (2 screws on top of microwave, then slide cover to the left, then forward) Removed control panel (1 screw at top of panel) then removed the two screws that hold in the door switch assembly. (these you will only see by opening the microwave). Located lower door switch, removed connecting wires, and pulled switch by releasing small plastic tab which held it in. Put new switch in place, reconnected wires, then reconnected door switch assembly. Reconnected control panel, and then put the vent cover back on. Tested microwave and it no longer runs when the door is open. Super easy fix, and was done in under 5 minutes.