depends on model...sometimes the front/top is removed by pressing in on hidden tabs between the top and sides. (can use a dull table/butter knife) Others are removed by separating rear and all sides/top. Check inbetween sides/top by looking/pushing tub aside to see inside top/sides. If you see screws holding them together, then it is a rear/top-sides separated model.
Begin with screws on back of controls, and two in front. Then remove all screws on back, including the water inlets and outlets. Back should be loose. Controls lift up, disconnect lid switch connection, back lifts up an inch or so, and they separate. Frame holds motor and basket, wiring is laced onto back with clips, move end of clips to open.
Wash-o-Bubz, March 2009