Yes, the headlight assembly needs to be removed to change the parking light. Since your X5 was built after 10/03, the top part of the front bumper cover needs to be removed so the headlight assembly can move forward. I have the pre 10/3 type so someone else will need to chime in on bumper cover removal. I do know it is only secured by, I think, 8 screws. Some are visible with the hood open and the others are covered by round plugs.

The headlight assembly is secured at 4 points. 2 on top of the assembly and 2 behind and at the bottom of the assembly. Not sure about the 3.0D but you may have to remove the air filter assembly to get access to the bottom screws. You then can pull the headlight assembly forward enough to get to the parking light bulb. Be sure to mark the location of the assembly on the headlight assembly tabs or better yet, in addition, turn on the bright lights and mark where the headlights are aimed on a garage wall in front of where you parked. You may want to replace all the bulbs while you have the bumper cover off.

All in all it is not difficult. I do agree it is quite a bit more work than it should be. One the other hand, I upgraded my headlights about 6 months ago and the parking light bulbs were the original bulbs and still fine so it is not something that needs to be done often.

I don't know if there is a DIY. Did you search headlight removal or DIY section?

__________________
X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas