If you choose to accomplish fixes on your own TGB 303R 50 then it is usually a great idea to possess a Workshop Manual for personal reference in case that you want to know the best ways to strip off a specific part including Door and fit it again in the right way.
TGB 303R 50 Workshop Manuals will give you exact diagnostic wisdom for your vehicle therefore if something is faulty it will help you figure out what the problem is and tips on how to fix it. You can then evaluate if this can be achieved on your own or in case the job is just too big you can still book your 303R 50 right into a trusted repair garage.
TGB 303R 50 manual