Comment by ssl-3

Same on my 14-year-old Honda van. The sane way to replace the HID bulbs (or the ballast or the ignitor, because HID things) is to remove the headlight housings, and the first step of doing that is removing the front bumper cover. It's not completely awful, but it's not exactly awesome either.

The less-sane way to replace just-the-bulb is from the top. It seems like it should be faster, and it sure does look easier, but it's a blind one-handed process with little fiddly bits to manipulate. There's not enough room to add a reasonably-stout glove to that hand, and there wouldn't be enough dexterity and tactile sense if there were. Consequently, there will be blood. I'm told that it's a lot more practical to swap a bulb in-situ with the halogen housings (as those don't have as much depth to them as the ones for HID), but my Honda is not so-endowed.

Part of this is because, AFAICT, the headlight assemblies are structural. They tie into several other assemblies and help hold the front of the vehicle together.

(A pedestrian Buick or Chevrolet from ~20 years ago is very different: To remove a headlight assembly, just lift up on a couple of heavy nylon straps and the whole shebang basically just falls out. It takes seconds. Reinstallation is very nearly as quick.)