If you choose to undertake adjustments on your own BMW F 800 GS then it is always a good plan to own a Workshop Manual for personal reference if perhaps you need to know how to take out a specific part much like the Door and install it again safely.
BMW F 800 GS Workshop Manuals offers clear special diagnostic information for your vehicle so if something is wrong it will help you understand what the situation is and tips to fix it. You will be able to assess if you can do this yourself or that the job is just too big it is possible to book your F 800 GS right into a nearby mechanic.
BMW F 800 GS manual