A member by the name of "twinspoppa" posted a great DIY for pulling off the bumper and replacing the xenon headlight bulbs. You should be able to search it out. I did it all myself about 2 weeks ago. It took about an hour.

Don't be afraid of the high voltage warning stickers. The ballast is attached directly to the bulb. The only high-voltage point is the bulb socket. The ballasts are designed with neat mechanical safety device that ejects the power cord as soon as you remove the ballast. On top of all that, you have to unplug the power supply to the housing in order to remove it from the car.

There is high voltage in the system, but you would have to go out of your way to actually expose yourself to it. I think those stickers are on there to scare people into paying the dealer to change the bulbs!