tell me about it, same as my ute, but i liv ein melbouren, a mess of wiress and a heater that didnt work. You can open it with those two clips and a phipis head screw driver and the core slides out once disoncected. (i found mine ran 10deg farenheight cooler on the coolant temp guage too).
You can hook the wires from the motor, one earth and the other to another independent switch (make sure you use a fuse) relegating the stock swiths to decoration status. works a treat for demisitng. Or go to the wreckers and stael the bits from a 120y.