If you want to execute auto repairs to your Veli VL90GY then it is usually recommended to have access to a Workshop Manual to use as reference in the event that you need to know how you can take out a certain component for instance the Brake Pads and fit it again effectively.
Veli VL90GY Workshop Manuals will give particular diagnostic facts for your car so if something is playing up it can help you work out what the situation is and easy methods to fix it. You can then evaluate if this can be done yourself or in the event the job is too big you can actually book your VL90GY right into a nearby repair garage.
Veli VL90GY manual