Ditto above...and it looks like you have an 06...so that means you either have the bi-xenon headlamps or the adaptive bi-xenon headlamps...and if you also have the headlamp washers...you're going to have to remove the front bumper cover (really easy if you follow the DIY on xoutpost.com).
And since the bumper cover needs to come off to get to the DS2 bulbs...you might as well replace both so that you don't have to go back in to do the other side if it goes out no longer after. Plus, two new bulbs will have the same luminosity instead of the one new bulb be brighter than the older bulb.
Not trying to scare you...but again, if you have the headlamp washers...the headlight assembly is not going to come all the way out...which makes it nearly impossible to get to all the screws holding the covers on etc to get to the bulb. You'll need a lot of dexterity & ability to work in tight quarters...possibly blind or use of a mirror, a good light source, and magnetic tools if you plan to change the bulbs without fully removing the headlight assembly from the vehicle.
Remove the bumper cover (piece of cake) and the headlamp assemblies from the vehicle (piece of cake) and changing the bulbs will be "a piece of cake". Trying to change the bulbs with the headlamp assembly half removed from the vehicle...and you have a long tedious & frustrating job ahead of you.
