From the KitchenAid Manual:
The water filter is located in the upper right-hand corner of the
Replacing the Water Filter
To purchase a replacement water filter, model 67003523 Part
Number 4396395, contact your dealer or call 1-800-442-9991
U.S.A. or 1-800-807-6777 Canada.
IMPORTANT: Air trapped in the water system may cause water
and filter to eject. Always dispense water for at least 2 minutes
before removing the filter or blue bypass cap.
1. Turn filter counterclockwise to remove.
2. Remove sealing label from replacement filter and insert the
filter end into the filter head.
3. Turn the filter clockwise until it stops. Snap the filter cover
4. Flush the water system. Depending on your model, see
"Water Dispenser" or "Water and Ice Dispensers."
NOTE: The dispenser feature may be used without a water filter
installed. Your water will not be filtered. If this option is chosen,
replace the filter with the blue bypass cap.