Replacing Ignition Cylinder

[Mornelithe]

Hello,
I just purchased a 1996 318Ti, and was informed by the previous owner that there was an issue w/ the ignition cylinder in the vehicle. He'd bought a replacement already, but had never gotten around to fixing it because he found a way to rig it to work correctly. So, naturally, after the car exchanges hands, it dies. Oh well, no biggie, my question is (and I have looked through the rest of the forums, sorry if I missed it in a previous thread) how does one go about replacing the ignition cylinder. I'll be doing it myself w/ the assistance of a friend of mine who has a shop. But, he's never worked on the ignition of a BMW before. So, does it require a special tool, or is there something else I'm missing?

Thank you very much,

Brian