If the headlight of your BMW vehicle turns to pink color. it means that the factory xenon headlight bulb on its way failure. How can we replace the hid bulbs? Just follow my steps.
Turn all lights off, remove fob and remove headlight fuse if you like! And refer to my image below, the yellow area is headlight back cover and blue arrow is where you can best access the working area.
Refer to the workshop manual from X5 E70, not exactly but the turning direction is same.
And this is the close picture to the dust color behind the retrofitting headlight housing.
While we want to remove the bulb, we need to disconnect power plug from bulb seat first.
A new and high-quality D1S hid bulbs are necessary, I recommend you buy from Philips, Osram.
You need open the retainer ring on the old hid bulb and transfer it to the new one, red arrow show the weak point of the bulb.
For the installation, it is just reverse to how to remove the old hid bulb, and make sure that you do not touch any part of bulb, in case touched then use rubbing alcohol clean it.
Besides, make sure retainer ring and power plug are seated firmly.
Then, I believe you have done it perfectly. I suggest you to replace both side together because while one bulb die, another one will also die soon.
If any question, please leave me a comment.