If you want to accomplish fixes on your BMW R 850 then it is always recommended to have access to a Workshop Manual for a reference in the event that you want to know the best ways to strip off a specific component such as the Clutch and match it again perfectly.
BMW R 850 Workshop Manuals gives you distinct diagnostic guidelines with regards to your automobile so if something is wrong it can help you work out what the issue is and some ways to repair it. You will be able to determine if this can be achieved yourself or in case the job is simply too big you can still book your R 850 right into a suitable friendly mechanic.
BMW R 850 manual