http://lighting.mbz.org/tech/how_to/relays
http://lighting.mbz.org/tech/how_to/aim
http://www.mbca.org/w124.htm
also search this site for a post called "procedure to convert connectors for euro headlights
This was a post by barrie that explains it quite well.
With all that information at your fingertips you should have no problems. I have all the sites I posted plus a couple of threads here printed and ready to be used for saturday's install.
Alon