In the engine, the ECT sensor can be found in the water outlet at its leftmost end. To take it out, remove first of all the engine cover and then the air intake duct. Then drain some coolant from the engine to reduce spillage. Then, remove the electrical connector from the ECT sensor. Remove fasteners from engine and discard sealing washer; use new one instead. To fix this back requires reversing. Lastly refill cooling system.