Gerald, The most difficult issue is removing the dishwasher from under the counter (if its an under counter model).
1) Disconnect electrical connection (2 wire nuts, ground wire & clamp).
2) Secure water source to unit. Remove 3/8" tubing or hose from water valve just behind access cover.
3) Remove the 2 screws At the top of the unit just above the door (below the counter top ledge).
4) Lower the front of the unit by adjusting the leveling front feet upward approximately 1"-2". Remember, when reinstalling you must level the unit again.
5) Tie a "tag line" (string) to the water tubing / hose and also the electrical wire. This helps when reinstalling.
6) Now gently pull the unit forward, pay particular attention to the insulation on the top and sides, they like to hang-up on the unfinished parts of your space. I like having a "yard stick" handy, this works well to keep insulation reasonably in place.
7) With the dishwasher exposed, you can easily access the under side and the pump. I believe there's one bolt, an electrical connection, and rotate the housing counter-clockwise and its out!
Good Hunting!