How do I remove Head Light assembly on my 1999 Lexus RX 300

John, needs to be scanned to determine fault.

have a tester handy.unplug the light and then turn on the headlights.with tester on 12 volts test plug to see if you have 12 volts. if not the plug is properly corroded or shorted .

sounds like low fuel pressure could be an array of things no engine light? even if no check engine light have it scanned for trouble codes its free at auto zone

loose bolt A (but don't remove)
and turn bolt B anticlockwise till ur belt loose
if its not loosing the belt bolt B will come out then pull the belt up and down
then remove and fix the belt

did the lock smith cut key with resister in in maybee not gotta go to dealer get one cut then put old key in start car then turn of remove key put new key in turn on till security light goes out then start car

Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Lift the hatch. The tall center light is located behind the upper hatch inside panel. There are two panels need to remove. One panel is on the right, the other on the left. To remove the panels you have to use flat screw driver to pry out the panel in several locations. (These panels are secured by several small metal clips.) Be careful to collect all these clips and replace them on the back of the panel. You will need these clips to replace the panel later on. After remove the panels, you will be able to locate the screws on the tall center stop light assembly. Remove those screws and cover. After replacing light bulb. Assemble everything in reverse order. Remember, the metal clips have to set on the back of the two panels not the car body.

Just found this site with your answer.
http://www.toyotanation.com/forum/showthread.php?t=269762

take out screwws on light remove bad lightbulb then replace lightbulb

First you need to lift the hatch. There are two screws under plastic caps. Remove the caps and you will be able to unscrew these screws. Carefully using a flat screw driver to pry out the tail light assembly. It have to plastic pin that attached to the car body. do not break the pin. After you pry out the tail light assembly, you will be able to replace the light bulb. Replace everything in a reverse order.

i understand why you want to do it yourself - it's expensive to have it done by a mechanic. that's because it's a major job to remove the engine, takes 4-5 hrs. i avoided having it done by having an honest mechanic i've been going to for a long time do something else (sorry, i don't know what) that fixed the problem temporarily. he told me it must be done after 90k miles or so, so i'm saving up.