Product review (5 stars): Great replacement
If you have a small size socket set you can do this installation.  Liberally loosen, or remove, the two socket head screws holding your old unit in place to remove it.  (Don't worry, water won't flow from the line.)  Pinch the sides of the wiring harness clamp to remove it from the freezer receptacle.  Compare the the wiring harnesses included with the new unit to see which one you need.  Plug in the applicable harness to the new unit and plug the other end of the harness into the freezer receptacle.  Put the unit in place and tighten the screws.  You are done!  Hint 1.  If you removed the screws,  put the forward screw in very loosely and  hang the new unit on that screw.  Then, holding the unit in place  install the rear screw. Hint 2.  Tape the second screw into  the socket with a small piece of masking tape to keep it from falling out of the socket while you  screw it in.