I recommend VDO repair, especially if you live in Southern California. This kind of work is all they do. I had mine done there just yesterday. They have a special rate of $250 for locals, the work is done in Huntington Beach, in 2 hours, while you wait. When its done they run the diagnostics for you to show that everything works perfectly again, and you are on your way. There were 8 or 10 units there shipped from shops all over waiting to be done while I was there.
Initially I had called BMW about this. They asked me all the questions previous posts inicated they would, and then I didn't hear a thing from them. I called again once more, but never heard from BMW again. Since my 2003 had 99000 miles on it, I decided I was going to get at most 25% off a BMW price, so I didn't persist with BMW. Even my local independent shop wanted $850!
I'm not mechanically inclined and have never done any substantive auto work. But taking the instrument cluster out is not hard. There are some directions and photos on vdorepair's website, and a better clip showing the process on YouTube. You just need a #10 Torx and a Phillips screwdriver - that's it. Disconnect the battery first and you'll have it out in 10 minutes. My only problem was I couldn't get the electrical connection to come out of the back of the instrument panel dimming switch, so I just left it connected and rotated the face plate 180 degrees to the left to get it out of the way. Really if I could do it anyone can. So I recommend you take it out yourself and send it off to vdo repair.