When renewing a bulb always remember that it can be very hot if the light just been in use. Check the bulb contacts and holder for good metal to metal contact, cleaning any corrosion or dirt before installing a new bulb. For bayonet type bulbs, make sure the live contacts are making firm contact with the bulb contact. Use the correct rating for the new bulb, and be sure that it is clean, especially headlight and foglight bulbs. When handling quartz halogen bulbs, make sure to use tissue or clean cloth when handling the bulb to ensure that you do not touch the glass as it will cause blackening and premature failure if it gets dirty due to grease, and if it does touch the glass, be sure to clean it with methylated spirit. For halogen H7 bulbs, the bonnet should be opened, remove the outer plastic cover, disconnect the wiring plug, release the retaining clip and pull out the old bulb to ensure the new bulb is fitted without touching the glass. For HB3 and H9 bulbs, open the bonnet and remove the inner plastic cover, disconnect the wiring plug and twist the bulbholder to remove it. Xenon Bulbs because of the high pressure and voltage involve in the process, must be handled with caution, disconnect the battery, open the Bonnet, take out the igniter/ballast and similar processes to replace the bulb by making sure you don't touch the glass. For the front sidelights on V70 models, open the bonnet, remove the dipped beam cover and pull the bulbholder without disconnecting the wiring. For S80 models, remove the front direction indicator and twist the bulbholder and pull the bulb. For foglights, access from behind the light unit, twist the bulbholder to release the bulbholder, and remove the bulb. For rear light clusters on V70 models, access from the luggage compartment, remove the speaker grille, and twist on the bulbholder to remove it. On S80 models, unclip the access panel and release the bulbholder assembly. The high-level brake light may need to be replaced entirely if it stops working and for number plate lights, undo the securing screw and rotate the bulbholder to undo it. For door mirror ground lights, turn over the mirror glass, remove the retaining clip and pull back the light unit. For side marker lights carefully prise out the front edge and twist the bulbholder to remove the light.