It's been 2 years since I installed them, and it looks like I'll need to replace a dead ballast. I mounted the ones for the headlights on the very commonly used "shelf" that you can access by removing the wheel wells. I remember taking off the wheels to get in there. Is that definitely necessary? Or would I spend more time not having enough room than I'd spend if I just jacked up the car and took off the wheel?

 

either through the wheel well by removing the tire or take off the front bumper and pull the headlights out a bit

 

If your talking about the space underneath and behind the headlight.... Just take the front bumper off...... i dunno how you mounted them? double sided tape or rivet a bracket that hold them in place but it will save you some frustration. just my 2

 

If you turn the wheels all the way to the right and start on the left wheel well, You're able to pull out the clips and reach in through the wheel well without taking off the wheel. I think The shelf everyone refers to is the metal tab that holds one of the clips for the wheel well in so it should be right on front of you. It's a tight squeeze but i was also able to reach up and change the bulb. I did my entire hid install this way.