How do I replace the Door interlock?
How do I replace the door inter lock?
Here is a link to just one supplier for the part that I think you are talking about.
If it is not the one then here is a link, showing all the parts for your microwave oven. (again from the same supplier - there are others just search online, using Kenmore 401.80093010 parts in the search box).
Here is a link which shows how to remove/replace the filters in your oven. Click on the Next Page link to finish reading the instructions.