you need to do this a retrofit xenon kit, and thats all in all about 2k € only the parts, and about 1 day work. if you only want to have the angle eyes, i suggest you some depo headlights. i also take these for my car, and its only about 1/10 of the price of real xenon.
http://bmwfans.info/parts/catalog/E8..._headlights-2/