A DIY on removing, installing, and wiring 2001+ (facelift) headlights in a pre 9/00 car. It’s actually a pretty simple process if you’re careful and patient.

Hella OE Xenon E39 Projectors with Celis Technology, European Spec: https://www.umnitza.com/browse-by-car-model/bmw/5-series/e39/hella-oe-xenon-e39-projectors-with-celis-technology.html

Link to Bekkers adapter to avoid splicing the headlight wires!
http://www.bekkers.com/Merchant2/merchant.mvc?Store_Code=BI&Screen=PROD&Product_Code=63120025497_499

E39Source WEBSITE: http://www.E39Source.com

BMW M3Source: http://www.youtube.com/E65Source

BMW E46Source: https://www.youtube.com/user/E46SourceE39Source