If you want to conduct repairs on your Veli KING50 then it will always be recommended to possess a Workshop Manual to use as reference in case that you need to know simple methods to take out a particular component including Brake Discs and install it again in the right way.
Veli KING50 Workshop Manuals will give you specific diagnostic information for your vehicle therefore if something is faulty it helps you figure out what the issue is and how you can fix it. Then you are able to evaluate if you can do this by yourself or that the job is just too big you could make a booking for your KING50 in with a suitable repair garage.
Veli KING50 manual