If you want to accomplish adjustments for your BMW R80 then it is always recommended to have access to a Workshop Manual to use as a reference in the event that you need to know the best way to take out a particular part such as the Door and fit it again properly.
BMW R80 Workshop Manuals provide you with distinct diagnostic information with regards to your vehicle so if something is not working it helps you ascertain what the issue is and methods to fix it. You will be able to analyse if this can be achieved yourself or if the job is simply too big you are able to book your R80 right into a trusted car garage.
BMW R80 manual