Turn off the water shut-off valve to your home via the water main, then run water in a sink to remove pressure from the line. Turn off the faucet when water stops coming out.
Locate the closest vertical water pipe to the area where you plan to keep the refrigerator. If that pipe doesn't have a shut-off valve connected to it, you must install one. Cut out a section of pipe, with a hacksaw, that will allow you to solder a shut-off valve into the pipe. Place flux around the cut ends of the pipe and on the ends of the shut-off valve. Place the valve between the cut pipes and head the ends with a blowtorch. As you heat the ends, Run a stick of pipe solder around the joints to create a soldered joint.
Drill a ¼-inch hole in the water pipe with a hand drill and a drill bit. Only drill through one side of the pipe, not the entire pipe.
Measure the distance between the hole in the water pipe to the front of your refrigerator with a tape measure. Add additional length to allow a bend in the pipe; an extra 6 inches is usually sufficient. Cut a pipe of flexible copper tubing to match that length. Again, use a hacksaw but work to keep the ends of the tubing flat.
Place the saddle-type shut-off valve into the ¼-inch hole and secure it with the built-in clamp. Use a flat-head screwdriver to secure the clamp. Tighten until the sealing washer that presses up against the side of the tubing starts to swell. Don't overtighten as you may crush the flexible tubing.
Place a compression nut then a compression sleeve onto the flexible tubing. Wrap plumber's tape around the threads on the saddle-type shut-off valve, then secure the compression nut onto the saddle valve with a wrench.
Place the loose end of the flexible tubing into a bucket and turn on the water supply. Run the water until the water comes out of the tubing clear. Once done, turn off the water supply again.
Route the flexible tubing across the floor under the refrigerator until it rests next to the union mounted on the lower front of the refrigerator behind the lower front panel.
Place a compression nut and a compression sleeve onto the flexible tubing. Wrap plumber's tape around the threads on the union, then connect the tubing to the union. Use a wrench to tighten the compression nut.
Turn on the water supply and check for leaks. If you locate any, tighten the connections until they stop.