One should always remember that the bulb when being replaced may be extremely hot if the light has just been in use, and always clean metal to metal contact between the bulb and the bulb contacts and holder may be corroded or dirty. For bayonet-type bulbs, assure oneself that the contacts make a proper contact with the bulb contact, and make certain that the new bulb is of correct rating and clean especially the headlight and 
Fog Light bulbs. For halogen bulbs, use the wire connector with the external clips to release, and the bulb holder assembly rotating in anti-clockwise direction for removal. Do not touch the glass part of the new bulb through bare hand, rather use a tissue paper or a clean cloth as this may cause very rapid bulb failure through condensation and oil. On the Xenon bulbs, unscrew the battery negative lead, and then remove the plastic cover together with the igniter unit, and then twist the retaining ring to release the Xenon bulb. For front parking lights, the bulb holder has to be turned in an anti-clockwise position to remove it while for front direction indicators you have to push the tab and pull the clip before disconnecting the wiring connector. They are relatively easy to destroy: side marker lights are inserted by pushing the lens forward to remove it and fog ones can be pried from the bumper; the bulb is part of the holder. Rear light clusters - with bulb holder, the retaining clip or fastener should be unlocked to detach the holder after which the bulb can be twisted anti-clockwise to unlock. Trunk lid-mounted lights have clips that have to be removed in order to reach the bulb holder; tailgate lights involve removing the entire light unit, plus the trim panel. The high-mounted stop-light requires removal of its retaining clips and extraction of the wiring connector while in the case of the license plate light one has to pry out the lens to access the bulb, assure that its position is secure after replacement.