How To: Change Halogen Headlamp / Headlight bulb A video comparison of 2006 Prius with X-Treme Power versus 2005 Prius with OEM bulbs. These pair of bulbs are availble at your local automotive stores for $40-$50 plus tax. I got a pair from powerbulbs.com for $47 shipped. Step By Step Instructions by Tideland Prius for Passenger side and Driver side Bulbs 1. Remove all 6 clips holding down the front cover. The "screw" needs to be elevated relative to the ring in order to make removal easier 2. Remove cover and set aside. 3. Focus your attention to the passenger side of the car. You will see the vent that leads to the engine air filter box 4. Locate the flathead button and use a flat blade screwdriver to lift it up. Once the button is up, you may remove the vent. It's up to you whether to leave the button pin there or not but just don't lose it! 5. Start with the passenger side cause that's the easiest. Unplug the socket from the base of the bulb and set it somewhere where you can retrieve it later. 6. Locate the rubber seal. Rotate it anti-clockwise. A few degrees is enough and it should come loose. Once loose, wiggle it to remove. 7. Locate a spring lever/catch. This lever holds the bulb in place. On the passenger side, if you were to look at the headlight straight on from the outside, it would be ~ "NW" or the top left side. Important! When you locate the lever, MAKE A MENTAL NOTE OF HOW IT IS REMOVED AND REPLACED. It'll make it easier when you reverse the steps as you cannot really see the back of the headlights. 8. For the passenger side, push the lever towards you and up. Once loose, swing it away. You might have to move it around a black wire (not sure what that wire is). Note the bulb will be loose at this point. At this point, you may attempt to put the lever back to get a feel of how far to push the lever towards you before you push down and let the lever catch. There is quite a bit of resistance. 9. Once you're done, carefully remove the bulb. You may have to move it around wires and the lever. 10. Replace the bulb with your new one. Again be careful when manoeuvring the bulb around the wires and the lever. 11. Once the bulb is in the headlight housing, look from the outside and make sure it's set properly and firmly. 12. Carefully replace the lever and make sure the bulb doesn't move out of place in the process. 13. When the lever's back in place, find the bulb base and move it to confirm that the bulb doesn't move. Plug the socket back into the bulb and test that the bulb works. 14. If everything's fine, then proceed to replace the rubber seal. This is the hard part and will probably take the longest time. Hint: you can put your finger through the rubber boot hole, guide it to the base of the bulb, and then push down. (Thanks to ScottY for that!) 15. The rubber seal has to sit just right so that when you rotate it clockwise, it'll lock, otherwise, it'll just rotate and nothing will happen. The best way I've found is to grab hold of the seal around the edges with your hand. This way, when you put the seal back, you can get a feel of where the outer edges of the headlight housing is and where to seat the seal. Once you think it's in, rotate it and see if it locks. THere is no click or anything so as long as it doesn't move on its own AND you can access the base of the bulb with the socket, you're fine 16. Replace the socket 17. Do the same for the driver's side. This one is a bit harder because access is tight. You can remove the fuse box cover if you wish. The top part of the cover comes off easily. The bottom part with a single clip needs a bit of force. Video installation guide by usbseawolf2000 for the driver side: Edited by Tideland Prius: Click here for extra information on removing the fuse box as reported by Boo 1 - Remove the Relay/Fuse box cover. Disconnect the headlamp wire. Twist counter-clockwise (unscrew motion) to remove the rubber boot. 2 - A view of the removed rubber boot - A rear view of the bulb and how it is being held. 3 - Unclip the lever holding the bulb. 4 - How to position the H4 bulb inside the headlamp. Tips from kvdsr: 1- "Clockwise" means different things depending on if you're looking at the rubber boot from the front or the back. I prefer to think that the boot works the same as a jar lid - which you turn left to remove, right to tighten. The two rectangular "ears" on the boot make excellent leverage points for your thumb and forefinger - as you pointed out on this most recent post. 2- Once you have "unscrewed" the boot/jar lid a few inches to the left, it will stop moving. When it hits this "stop" point, it is in position to be lifted out. MAKE A MENTAL NOTE on the position that the ears are in at this stop point. When you reinstall the boot, position it so that the ears are at the stop point, and you should be able to push down on the boot till it bottoms out evenly. Tighten the boot to the right a few inches, and it will again reach a "stop" point. It is now locked in place.