If you have to carry out maintenance tasks on your Aprilia ETX 635 then it is always a good plan to have a Workshop Manual to use as a reference in case that you need to know tips to take out a certain component for example the Gearbox and install it again in the correct manner.
Aprilia ETX 635 Workshop Manuals can offer you identifiable diagnostic guidelines on your car so if something is broken it helps you work out what the problem is and tips to correct it. You will be able to decide if this can be done yourself or if the job is too big you are able to book your ETX 635 into a nearby garage.
Aprilia ETX 635 manual