Just get it took off- its a mechanical system anyway the only electric involved are the lights on the dash.

If he disconnects the plug the lights will come on permanantly but it wont piss him off.

Its belt driven off the drive shafts.

Is that more helpfull?

If he wants the light to go off he just needs to cross the wires on the plug and connect the circuit (if I remember correctly on this bit)

Jake