Pull the power cord out of the wall outlet to avoid electrocution. Turn off the hot and cold water behind the appliance. Release the clamps securing the drain and water supply hoses to the ports on the back panel. Direct the water that spills from the hoses into a bucket or a floor drain.
Unfasten the eight hex screws securing the back panel to the washer. Remove the panel and set it aside with the removed hex screws.
Find the motor and belt drive assembly underneath the tub on the left side of the washer cabinet. Slip the old belt off the drive and motor pulleys. Check the floor of the washer cabinet if you don't see the belt; it may have snapped and fallen off the drive system.
Turn the washer around so that it faces the wall. Tip the washer forward to rest against the wall so you can access the three bolts on the underside of the base; these bolts hold the motor assembly in place. Loosen the bolts, using a socket wrench, and slide the motor toward you.
Fit the replacement belt onto the drive and motor pulleys. Slide the motor away from you to set the belt tension; the belt should be taut, but not overly tight. Tighten the bolts on the underside of the base once you've achieved the desired belt tension.