I have included a set of illustrated instructions (See below). These should step you through the process of cleaning the filter in the drain pump of your washer.
Make sure unplug the washer before attempting any repair.
Remove the two screws holding the bottom panel in place. The pump may one screw in the front base. If you remove the screw, the pump can be lifted to slide a pan under it to catch any left over water. Remove the filter cover slowly to allow the water to drain in the pan. Once the water is out remove the cover and clean the filter. Once the filter is clean, reassemble in the reverse order. Please resubmit another question for further assistance.
Here is a link to buy the parts needed from our parts web site
Sears Parts Direct
If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician. Here is a link for the website:
Sears Home Services