Bought a new drain pump and a new flapper valve. The old flapper valve looked larger. I emptied the bottom of the dishwasher using a shop vac. Pulled out from under counter and laid on side. Had to loosen dishwasher motor and pull out slightly to provide access to all the screws from the drain pump, but it was still pretty easy. The new pump had a different shape to the gasket, but it doesn't leak. New pump much quieter, doesn't "pulse" like the old one. I assume the misshapen flapper valve caused the "pulsing" and led to the original pump failure. Upon righting and re-installing, I found that the dishwasher water line started leaking; there must have been too much tension on the line when it was laid down. I replaced the line and everything works fine. Requires torx 20.