To install a filter in an ice maker, turn off the supply valve to the water line, cut off a section of the line, install the filter's fitting nuts and connect the filter to the cut ends of the tube. Open the supply valve to let water pass through.
Begin by moving the refrigerator away from the wall, unplugging it and locating the plastic or copper 1/4-inch water line. Find the cold water supply valve for this line, which may be under the sink or behind the refrigerator, and turn it off. Place a bucket under the water line, then use a wrench to unhook it from the fridge. Drain out all residual water. Use a tubing cutter or PVC cutter to cut off a section of the line close to the fridge to ensure enough space for the filter, approximately 12 inches.
Slide one of the filter's fitting nuts and one of the compression washers onto each end of the line. Insert the water filter with the arrow on the device pointed upwards, and screw the fitting nuts onto the filter's threaded nozzles starting with the tubing on the upper end of the filter. Re-open the water supply valve, and check for leaks.