There are two nuts on the back of the headlight. One on the top corner the other on the bottom corner. You'll need a wrench. I think about a 8 or 10 mm if I remember correctly. Just open up the hood and slide the wrench onto the nut and turn. One of the nuts turns the light left/right, and other turns the light up/down. Thats how it is on my '97.
I'm not sure about where the light are meant to be hitting, say if you point them at a wall. Don't go too high or you blind people. I think they are meant to be just below the actually light housing on you 4runner. So if you measured from the ground to the headlight, then, parking on level ground, measure the same distance from the ground up a wall, make a mark on the wall and aim for that. Or just below it. Hope that makes sense.