To access the float switch remove the front panel located beneath the door. The panel is usually held in place with two screws either above or below the panel. It may be necessary to first open the door to the dishwasher to reach the screws over the panel, then close the door to remove the panel.
Before replacing the float switch, unplug the dishwasher or shut off the power at the fuse box or breaker panel to avoid an electrical shock hazard.
Note the location of the float in the dishwasher's tub and you will find the float switch beneath it in the access area. The switch has two wires connected to it. Label the wires and connections so that you can properly reconnect them later. The wires are connected with slip on connectors. Firmly pull the connectors off of the terminals (do not pull on the wire itself). You may need to use a pair of needle-nose pliers to remove the connectors. Inspect the connectors and the terminals for corrosion. If either is corroded they should be cleaned or replaced.
The float switch is attached by one or two small screws or a clip. The switch is also connected the the float assembly in the dishwasher's tub. Remove the screws or clip and carefully disconnect the switch from the float assembly.
Connect the new switch to the float assembly, fasten the switch in place with the screws or clip, reconnect the wires, replace the access panel and restore the electricity.