If you have to undertake repairs on your own Kreidler Mustang 50 then it will always be a good idea to have a Workshop Manual to use as personal reference in case that you need to know methods to take out a specific part such as the Brake Pads and install it again in the right way.
Kreidler Mustang 50 Workshop Manuals gives you detailed diagnostic info with regards to your vehicle therefore if something is not working it can help you figure out what the issue is and ways to resolve it. You can then analyse if this can be achieved on your own or that the job is too big you could make a booking for your Mustang 50 in to a decent garage.
Kreidler Mustang 50 manual