Just came across this guide for vanos repair/overhaul. Haven't read through it all as its a big read but looks to be very detailed and I've never come across it before. Thought it might be useful for everyone if they hadn't seen it.
http://www.beisansystems.com/procedu..._procedure.htm
http://www.beisansystems.com/procedu..._procedure.htm
http://www.beisansystems.com/procedu..._procedure.htm
http://www.beisansystems.com/procedu..._procedure.htm