Move the washer away from the wall to give yourself some room to maneuver around the appliance.
Place a level on top of the washer to determine where the washer is not level. Measure from front to back and from side to side. This will give you an idea of which foot or feet you need to adjust and how much.
Turn the leg or legs that you need to adjust with adjustable pliers until the washer appears to be level. Some washer models feature jam nuts just above the feet that must first be turned loose before you can turn the feet themselves.
Grab the washing machine from the top left and top right sides and shake the appliance to see how much it moves as you try to shake it. If the appliance appears to be stable, move on to the next step. If the washer moves a lot, repeat step 2 as many times as necessary.
Retighten the jam nuts if necessary. Push the washer back into its permanent location.