http://forums.5series.net/topic/8812...-drain-refill/
This link is for a 5 series DIY, but much if it is relevant because it is the same transmission. I think for DIY'ers one of the key things that you need to do is run the transmission through all the gears when refilling and at the prescribed temperature. I got my service kit from California Transmission Supply Company, which includes the correct BMW fluid (ZF Lifeguard6). I will be doing my service in the next week or so at 45K miles. I'm having a local transmission shop do the labor.
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BMW PPK V2, M3 26mm sway bar, M3 front control arm kit, M3 steering wheel, BMW 313 wheels w Michelin PSS