With the ignition off, open the bonnet. From behind the headlight unit, remove the rubber dust cover behind the bulb closest to the centre of the car. Reach in and carefully turn the back of the bulb holder about a tenth of a turn until it pops out. You can now carefully withdraw it so that the bulb is visible to work on. Remove it by pulling upwards carefully from the base of the bulb. When fitting the new bulb ensure that you do not touch the surface of the glass with your bare hands; doing so leaves oily deposits and can cause rapid failure of the bulb. Push the bulb into the holder, being careful not to damage the pins. Then reverse the removal procedure to refit, taking care not to get any wires caught when re-inserting the bulb holder.