Zero Clearance or Dado insert plate

I have a Ridgid R45171 Table saw. When it was invented the engineers all got together and said, nobody will ever want to replace the throat plate, ever. But just in case we will make one that does not fit and then sell it to the customers anyways. They all rejoiced and sprayed each other with Champaign or something like that. So I made one out of PVC. Here is how.