I have a Maytag DFB9000aax Series 11 disposer. Needs a new switch assembly. The old housing around the existing switch is corroded. How do I remove the switch? Also, I need a new rubber thrust washer (part #40). All sites say it's discontinued. The existing washer has a hole in the middle, exposing the shaft (I assume it's worn). Is it OK to use the unit with the existing washer? Should I just discard the unit and get a new disposer? With all parts neede, my repair will come to about $150.00.