There are no "bulb" in the cluster. To change the needles you need to do two things.
1) desolder the red LEDs on the circuit board and replace them with white ones
2) sand the red/orange film off the back of the needles themselves.
I copied a walkthrough on how to disassemble the cluster and swap out the LEDs from another forum some time ago. A search should bring it up. It was originally made by commie so that might be a good key word.
Alternately you could get a cluster from a '08.5-09 MS3, swap it out and have the dealer program the new cluster for you as those ones have white needles.