If you have to do auto repairs on your Veli VL90 6 then it will always be recommended to have a Workshop Manual to use as personal reference in case that you need to know methods to take off a particular component including Exhaust and match it again safely.
Veli VL90 6 Workshop Manuals provides exact diagnostic information for your car so if something is playing up it helps you work out what the issue is and some ways to resolve it. You can then evaluate if this can be done on your own or in case the job is too big it is possible to make a reservation for your VL90 6 right into a suitable repair garage.
Veli VL90 6 manual