wow, this is such a PITA, I replaced mine a couple weeks ago. It really helps if you take out the turn signal first, it's only held in by one bolt. Then remove the black plastic that's infront of the radiator, it's held on by a few screw/clip things. Then the light is held in by studs with black plastic nuts on them. The nuts have 2 prongs on them that keep them held into the housing. Looking at it from the side, <[---, that's the bolt coming through the housing, you have to push the 2 prongs in flush so that you can back it out through the hole in the housing. For me, this part was the most time consuming and I eventually used a flathead screwdriver to pry against the bolt and flip the light out. There's 3 bolts to do this to and then the light should come out. Disconnect the harness for the bulb and put the new one in. There are tracks on either side of the housing that guide the headlight into place. You may have to adjust the nuts on the bolts to have the light sit right in the housing and not stick out too far. It's pretty straight forward, but can just be really frustrating. Good luck, and just don't give up.
BTW, my replacement has more gap between it and the stock turn signal than the other side does. For this reason, I think I'm going to look into the one piece headlights cuz the gap just annoys me when I look at it.
Good luck,
~A.C.