Looked up the model number on the internet, found a diagram on AppliancePartsPros.com which led to part number for the user interface, also found "how-to video" on-site that included how to remove user interface panel.
When the part came it was an easy fix, remove defective user interface panel - remove 2 screws mounting lip, then remove 2 screws mounting panel, unplug 4 connectors in back, plug connectors into the new panel, mount new panel, and re-mount lip. Less than 10 minutes, the panel now works perfectly.