If you choose to do repairs on your own BMW R 606 then it is usually recommended to possess a Workshop Manual to use as a guide in the event you want to know ways to take off a particular part much like the Drive Shaft and fit it again in the right way.
BMW R 606 Workshop Manuals offers you identifiable diagnostic guidelines on your automobile so if something is wrong it can help you ascertain what the situation is and some ways to correct it. Then you are able to evaluate if this can be done by yourself or if the job is just too big you could book your R 606 right into a trusted friendly mechanic.
BMW R 606 manual