Just so happens I installed my new ignition barrel today. It is not a bad job and a search here for "ignition cylinder" will turn up some helpful threads complete with some diy instructions on removing the ignition barrel.

Removing the steering wheel for this job is totally unnecessary, although it's a fairly quick and easy procedure to do so anyway. Coincidently, I also removed the steering wheel today to repair some bad wires on the horn slip ring that were shorting and causing the horn to activate by itself. Not such a good thing when your driving through the grocery store parking lot waiting for the little old lady to cross.

Back to the ignition barrel... since yours actually broke off in there, you might have a tough time getting things to line up right so you can pull the barrel out. Basically, you need to remove the plastic ring around the key hole. It is actually an antennae that reads a microchip inside your key. The plastic might snap during removal - mine did. Then you'll need to insert a sturdy paper clip or small allen wrench into the little hole in the key cylinder. The tricky part is that you need your key inserted and turned about 50-60 degrees. Wait a minute... refer to:

http://www.bimmer.info/forum/showthr...ition+cylinder

and

http://evansweb.info/articles/2003/0...on-lock-barrel

I ordered my new ignition barrel and antennae from the local dealership. Together they cost around $125 I think. I needed to bring in current registration and title along with my driver's license so I could order the coded version by VIN so I could keep my ignition and door locks matching. The ignition barrel did come from Germany and took almost four weeks to arrive.

The good news is that installation is a breeze, since it is very easy to line up the key with the barrel out. Just pop it in, snap on the antennae ring and you're golden.

Also, once you get the original barrel out, you can start your car with a screwdriver while waiting for the new barrel to arrive. Not very sophisticated, but it does work. You may need to hold your key close to the antennae ring while starting the car with the screwdriver. I did.

One last thing, it seemed it was just the cylinder that went bad in my case, not the whole barrel. The end of the barrel that turns the ignition assembly was still together. It sounds like the mechanics that did John in CT's car replaced the entire ignition assembly reasoning broken bits could have gotten in there. I'd call BS on that too. Even if it broke off, I think you'd be okay removing the broken pieces and replacing just the ignition barrel. YMMV.