How do remove the old motor and install Part Number AP3875428?
ballet08
You have to remove the dishwasher from the cabinet to access the part. I believe you can use some instructions from one of our previous threads: http://forum.appliancepartspros.com/dishwasher-repair/176535-hums-but-wont-cycle-no-water-flow.html#post368518
This pump & motor assy is pretty similar to yours.
Here are the breakdown diagrams and http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5224237
Gene.