Yesterday I replaced my stock fogs with some cheapo led bulbs that I had bought for my 1st Gen before I traded it in. I just wanted to see how hard/easy it would be because I'm about to buy yellow fogs and I'm undecided on HID's or halogen bulbs. I was putting my summer wheels back on so I did it while I had the front of the car jacked up in the air and I just wanted to let everyone know that I read a lot of people saying that you have to remove the fender over the wheel well to remove the fog light housing. Mind you I don't have the biggest hands in the world but with the car jacked up I removed all of the screws/plastic push clips from left to right on the bottom of the front bumper. Then I dropped the plastic piece that covers the oil pan down and back so it wasn't in my way. IMO there was enough room to work with just this piece removed, it's all plastic down there so I found it quite easy to carefully push the bottom of the front bumper around and out of my way. I got my hand in with no problem even on the passenger side where the winshield wipeer bottle is. As a matter of fact it looked like I would have less room going in from the side than I did going in from the bottom. On the passenger side the wire harness was long enough to pull it completely out and let it hang about four inches, this made it very easy to switch bulbs. Again it looked like I had enough room to mount a ballast if need be with those pieces pulled down. The drivers side was a little more difficult but only because the wire harness wasn't long enough to pull it all the way down and out like on the passenger side. Heres the crazy part; I was able to stick both hands in on the drivers side and use my left hand to release the tab holding the bulb and use my right hand to pull the bulb out. It also looked like I had enough room to mount a ballast and such from here.
I think I read somewhere in this thread that someone else also did it this way and cursed the whole time lol. Luckily it wasn't that frustrating for me. I actually had a harder time doing this on my 1st Gen because both harnesses were short. I think the key is to jack the car up high enough to have room enough to work without your arms being so constricted and to carefully pull the plastic out of your way to give you some work space and you should be fine. I don't see why you would remove the fog light housing unless you were customizing it but for those that may ask, I would have had room to do this from here also. With the help of a flash light I was able to see the back of the fog light housing with no problem.
Remeber I just swapped bulbs and by no means am I saying that an HID install would be easy from the bottom but if I'm not mistaken I read in a few threads that the only way to do it is from the fender over the front wheels. After being in there myself IMO it's doable from the bottom.