If you want to accomplish maintenance tasks for your Veli VL150 4II then it will always be a good plan to have a Workshop Manual to keep just for a reference in case that you need to know techniques to strip off a specific part for example Door and install it again in the right way.
Veli VL150 4II Workshop Manuals will provide you with precise diagnostic details for your vehicle so if something is broken it can help you find out what the problem is and tips to resolve it. After that you can assess if this can be done by yourself or in the event the job is simply too big you can still book your VL150 4II right into a trusted garage.
Veli VL150 4II manual