Shut off the electricity for the refrigerator. Unplug the refrigerator or turn off the power at the main breaker for the circuit where the refrigerator is installed.
Cut the water supply for the refrigerator. Locate the nearest water supply valve, which, in most installations, should be beneath the nearest sink. One of the water supply valves will have two hoses running off: one to the sink above and one to the refrigerator. Turn the knob on the end of the valve clockwise to turn off the water supply.
Place a towel underneath the shutoff valve. Unscrew the coupling on the refrigerator water hose counterclockwise. Pull the hose off the supply valve. Wipe up any water that drips out with the towel.
Follow the water hose back to the refrigerator. You may need to pull the refrigerator out away from the wall to reach the water supply hose connection in the back. Hold the towel underneath the coupling where the water hose meets the refrigerator and unscrew with the wrench.
Place the hose in a nearby sink. In a small container, mix together a pint of warm water with a capful of bleach. Use a turkey baster to siphon up some of the bleach/water mixture. Squeeze the mixture into one end of the refrigerator water hose. Continue until all the bleach/water mixture is gone. Flush out the hose with cold water.
Wrap the oulet on the water supply valve with plumber's tape. Reconnect the refrigerator water hose coupling. Tighten with the wrench. Repeat this process for the connection on the refrigerator.
Restore the power to the refrigerator. Turn on the water supply by rotating the knob counterclockwise.