First - thank you for adjusting your headlamps, I regularly get blinded by people that don't care that their lights are all over the place.
A quick google for "X3 headlamp adjustment" found these links.

How do you adjust the halogen headlights on an X3? - Bimmerfest - BMW Forums
How to adjust headlights of BMW x3 2004 - FixYa
Headlight adjustment?? - Bimmerfest - BMW Forums
2005 X3 E83 Xenon Headlight Adjustment for France