Shut off electricity to the cooktop at the circuit breaker before starting any repair project. The Modern Maid cooktop secures to the counter or kitchen island with screws below the front edge. Remove the screws with a screwdriver to release the retainer bar underneath. The bar slides off so the cooktop can be raised at an angle. Use a metal rod or wooden dowel to support the Modern Maid.
Pull the knob off the front of the defective switch to reveal the metal rod on the surface. Two wires clip to the contacts on the back of each switch below the Modern Maid. Slide the pair of wires off of the contacts on the defective switch and note where each connects so you can hook them up to the new switch. With the wires out of the way, take out the screws holding the switch to the mounting plate under the cooktop. Now you can remove the old switch.
Place the new part in position under the Modern Maid and insert the metal rod for the control knob through the opening in the bottom of the cooktop. Secure the new part with the screws through the mounting plate. With the new switch in position, slide the two wires onto their respective contacts. Each wire has a metal connector for this purpose.
Hold the cooktop upright when removing the metal or wooden support. Lower the Modern Maid carefully to the top of the counter. When the appliance is flush with the counter, slide on the retainer bar to the front edge under the counter and secure it with the screws removed earlier. Switch on the electricity at the breaker to finish the repair and use the Modern Maid.