You must be somewhat skilled in connecting wires and fixing things. You could ask around your family for someone who is handy at fixing things. Replacing a start knob or switch shouldn't be very difficult. First be sure to UNPLUG the power cable before doing any work to it. You might be able to type that model number into EBAY and get an exact replacement switch. If you want those skills (fixing things), you should practice on something less dangerous before tackeling a major appliance. By the way... don't fool around with microwave ovens. They have several hidden dangers that can hurt an amateur repair person.