It may be possible to change one of the ballast (if we're talking about the aluminum boxes attached to the headlamp) on the headlamp but I needed to replace the entire headlamp housing, not just a bulb/ballast. The headlamp housing will not pass through the opening without removing the bumper cover. And just to clarify, while I removed all the fasteners that hold the bumper cover on and it was ready to drop, I was able to slide it forward (3-4"?) just enough to remove the headlamp assembly.