If it is a convertible dishwasher,it is easier since they are undercounter units converted to portables and you just have to remove the cabinet, wheels, drain and water lines to make it an undercounter again. For the regular units, you have to remove the wheels and top. The sides are not normally removeable since they hold the portable together. You have to remove the electric reel, drain and water hoses and purchase a new drain hose. Then you must cut openings in the side of the unit for the water, drain, and electric cord. Slide the unit into the opening, run the utilities through the holes. Connect the water, waste and electrical. The waste may have to go through an air gap depending on your codes. If you have a disposer, then the dishwasher/air gap drain can connect to its opening after the plug is knocked out of it. The connection to the hot water supply can be done in many ways depending on the type of connection you now have. The electric cord has to be plugged into an outlet with constant power, not the switched disposer outlet.