I've unscrewed the three screws that are visible, but there is clearly something else holding the headlight assembly into place and I can't figure it out.
All I need to do is change a parking light but I can't figure it out!

You dont need to remove the headlight assembly to replace the parking light bulb.
Sorry, I cant tell you how I did it but I know I did not remove the headlight assembly. I remember twisting my hand in odd shapes to get to it.

If you do want to remove the headlight assembly there is a post on the forum that tells you how. I did not bookmark it but I did read it. I remember that there is a bolt that is a PIA to get to.

Sorry I am not much help I guess. I was going to pull my headlights to clean them until I read how difficult it is to do.

But people do it a lot so I guess it isnt that difficult.

Now is that a Charlie Brown post or what

You do not want to try and remove the entire assembly. I did it last night and it sucks bad to get to the 4th bolt holding it in place.

The parking light (lowest orange bulb) is the stick-like assembly. You will have to turn it to the left (as if you were standing in the engine bay.

If your trying to the turn signal or daytime running light out, that one is easier and higher. Just needs to be turned then it comes out.

Here is a link to remove the whole assembly.
another blacked out headlight thread...DIY lots of pics.

You are missing the 4th bolt which "can" be a pita. You will notice in the 4th pic down that he goes through the fender well to get to the 4th bolt. I did the mod in the link and I was able to get to the 4th bolt by sticking my hand through the dust flap diagnally under the headlight with the hood up from the center of the bumper. You will not be able to see it but after feeling around for a while I got it. I do recommend the mod described in the link. It completely transformed the look of my 4 runner and I love it.

The previous posters are correct though. You do not need to remove the whole assembly to change the bulb.

I just swapped my headlights a little over a week ago. I was able to see the 4th bolt by unscrewing the fender liner and pulling it back. I shined a flashlight to see it, and I was able to use a socket wrench to undo it. Thankfully, the bolt is half the size of the other 3 so it's less of an effort to pull out. After that, don't forget the piece under the headlight is clipped in as well. I did not re-install the 4th bolt and they are secure with just the top 3.

X2. Exactly what I did when I removed mine to get retroed. I never reinstalled the "4th" bolt, doesn't need it. Unless of course you live in a 3rd world country where theft is rampant, only then would I use it.

Even then, they would have to get under the hood to do it!

Adding to an OLD thread here...I just swapped the headlight assemblies on our '06 Sport. I used these: Amazon.com: New Headlamp Headlight - OEM: 8117035451, OEM: 8113035471, Pair Set: Automotive

I didn't find that 4th bolt to be that big a deal. I got to it from under the front bumper, arm at an angle like the other poster. Didn't have to remove anything. Used a long 1/4" drive socket, you have to feel for it. Putting it back on wasn't much more difficult, start with nut in socket using just fingers to start.

About to remove the headlight assembly to replace with a newer one. For the 4th screw, should I jack my 4runner up to make it easier to remove the fender wall and get to the screw?

i used and intermediate socket on the last one inside the fender. just like everyone else has said real PITA

I replaced both of my assemblies. I removed the bumper cover. *shrug*

What’s less of a pain, removing the screw through the fender or removing the bumper cover?

If you mean the front marker lights, removing the assembly is overkill.

Start on the passenger side. From the engine compartment, shine a flashlight in the upper area of the headlight assembly closest to the outside of the vehicle and familiarize yourself with the layout. It’s close, but you will observe how things go together.

Pinch the clip on the plug where the plug joins the socket and pull off.

Use a deep 17mm socket and carefully fit over the plastic socket containing the bulb. Turn counterclockwise about 1/4 turn and pull out.

The driver side is more problematic, but can be done in the same way. Some remove the battery clamp and tilt the battery back a bit for easier access. If you have large hands you may need to do that.

Work patiently and deliberately.

the last bolt is hidden and accessed only through the tire fender well you have to pull back to reach it, here is a video showing how its done

YouTube

I don't know... I had time, access to the shop at work, and nothing better to do. lol