Moving a dishwasher means safely disconnecting three things at once: water, drain, and electrical. Because a dishwasher always holds some water in the pump and lines, draining it and controlling leaks is the theme of the whole job.
Pro tip: Keep the mounting screws and brackets in a labeled bag taped to the unit for reinstallation.
Watch out: Always shut off both the water supply and the breaker before disconnecting. Water plus electricity is a serious hazard.