Chock the front wheels, jack up the car, and support it on firmly based jack stands. From under the car, disconnect the downshift linkage rod from the transmission downshift lever. Apply a little penetrating oil to the downshift lever shaft and nut, allowing it to soak for a few minutes. Remove the transmission downshift outer lever retaining nut and lift away the lever, then remove the neutral start switch securing bolts. Disconnect the multi-wire connector from the neutral switch and lift away the switch. To reinstall, place the switch on the transmission and secure it finger-tight with the securing bolts. Move the selector lever to the 'N' (Neutral) position, rotate the switch, and fit a No. 43 drill bit into the gauge pin hole, ensuring the bit is inserted a full 0.48 in (12.30 mm) into the three holes of the switch. Tighten the switch securing bolts fully and remove the drill. Installation is the reverse of the removal procedure, and it is important to check that the engine starts only when the selector is in the 'N' and 'P' positions. The neutral start switch on the C3 transmission is not adjustable, so any fault will be due to a malfunctioning switch, wear on the internal actuating cam, or faulty wiring. If a fault is suspected, the switch should be replaced with a new one, using a new O-ring seal and tightening to the specified torque.