This is a fantastic tutorial. Thanks! I asked my local BMW provider for such a service last year and they said they had none. I'm going to apply this ASAP.
One other thing I'll add. I was one of the first to take ownership of a E93 in the front range in early 2007. I noticed overtime the top shuttered and moaned on operation, esp. on closing. It turned out the hydraulic fluid was low. The dealer charged the system to manufacturer spec. and it operated smoothly again, as expected. So i would recommend such a check up if your top is shuttering or sluggish.