Warning! The gas in gas-discharge lamps is under pressure. Therefore, the lamps may break if dropped or scratched on the glass surface. Use eye protection when handling lamps. If possible, hold the lamp only by the base. Do not touch the surface of the lamp with your fingers without first putting on gloves, because the fat present on the skin can cause the lamp to overheat and fail prematurely. If you do touch the surface of the lamp, wipe it with alcohol.
1. Disconnect the ground wire from the battery (see paragraph 1 of chapter 5).
2. Unscrew the upper headlight mounting bolts (Fig. 16.2).
Fig. 16.2. To detach the upper section of the headlight housing from the upper radiator cross member, remove the two bolts (the Toyota model is shown, similar for Lexus)
3. Remove the grille and bumper trim (see chapter 11).
4. On 1999-2003 Lexus models, remove the two headlight housing mounting nuts on the outer edge of the headlight housing. On 2004 and later Lexus models, remove the headlight housing mounting bolt located on the outer lower corner of the housing.
5. On Lexus models, release the locating pin on the upper support bracket by simply pulling the support bracket straight up.
6. Release the two headlight housing clips located on the underside of the housing (Fig. 16.6) and pull the housing out just enough to access the electrical connectors on the underside of the headlight assembly.
Fig. 16.6. To release the two headlight housing fasteners, grasp the headlight and gently pull it outward (the Toyota model is shown, similar for Lexus)
7. Disconnect the electrical connectors on the headlight housing (fig. 16.7, a). There are two electrical connectors for the headlights (Fig. 15.2) and a third connector for the turn signals/parking lights and side lights (fig. 16.7, b).
Fig. 16.7, a. Pull out the headlight housing and disconnect the electrical connectors of the headlights and turn signals/side lights. After installing the headlight housing, adjust the headlights using the vertical adjuster (A) (see paragraph 17)
Fig. 16.7, b. To disconnect the electrical connector of the front turn signal/parking light and side marker light, press the locking tab and disconnect the connector
8. If the headlight housing itself is damaged, you will need to replace it. But if the damage is only a broken headlight housing support bracket, Lexus and Toyota sell headlight housing support bracket repair kits.
9. Installation is performed in the reverse order of removal.
(The text is quoted from the source website toyotaman)
10. Finally, check the headlight adjustment (see paragraph 17).