Disconnect your existing washer and dryer unit. Turn off the hot and cold valves. Leave the hoses attached to the valves. Use pliers to unscrew the hoses at the base of the washer until the hoses come free from the washer. Pull the drainpipe from the base of the washer and disconnect the drainpipe from the tub or sink it was connected to. If your dryer is a gas dryer, shut off the gas valve and disconnect the gas line from the dryer with an adjustable wrench. Disconnect the vent hose from the dryer by removing any tape or clamps holding the vent pipe to the dryer.
Remove the washer and dryer from the room and take them out of the vicinity to make room for your new washer/dryer unit. Put the removed washer and dryer somewhere they will not obstruct your ability to get the new washer/dryer into the room.
Measure the space where the new washer/dryer unit will be installed to ensure you will be able to fit the new washer/dryer unit into the laundry area. Check ahead of time that the gas hose, water hoses and vent hose will be able to reach the connections on the back of the washer dryer. Also check that the electrical cords will reach the electrical outlets in the walls. It is better to know if there are problems ahead of time, since you'll be working in a tight space.
Move the washer/dryer unit into the space, leaving enough room to one side and behind the unit so that you can position yourself behind the washer/dryer and work. You may need to experiment with the position of the washer/dryer unit during this process. To reach some of the lower connections at the back of the unit, try lying on the ground, with your body on the side of the washer, legs in front and head and shoulders behind the washer. To reach higher connections, you should be able to stand.
Level the washer/dryer unit by tilting it onto two feet and twisting the elevated adjustable feet with an adjustable wrench.
Connect the hot water and cold water supply hoses to the rear of the washer. Be sure to connect the appropriate temperature of water to the appropriate connection at the back of the washer. Tighten the hoses with pliers. Plug the drain hose into the back of the washer, and use a zip tie to attach the other end to the utility sink or tub. Point the end of the drain hose into the tub so you can be certain it will drain into the sink.
Attach the dryer vent to the dryer with the clamp from the previous dryer unit. If you didn't have a clamp for the previous dryer unit, you need to purchase a clamp or dryer vent tape. Screw the gas hose to the back of the dryer, and tighten it with a wrench.
Dampen the connection of the gas hose at the back of the dryer with soapy water, and turn on the gas. If bubbles form, there is a leak, and the connection should be tightened.
Plug in the unit, and slowly turn on the water lines. You may need to stop and tighten the hoses where they connect to the washer, so watch for sprays of water. Run an empty cycle in the washer before attempting to wash a load of laundry.