If you wish to execute maintenance on your own Aprilia ETX 350 then it will always be a good plan to have a Workshop Manual to keep just for reference if you need to know the best ways to remove a specific component including Clutch and match it again perfectly.
Aprilia ETX 350 Workshop Manuals provide you with specified diagnostic wisdom for the vehicle therefore if something is wrong it helps you find out what the situation is and methods to repair it. After that you can assess if this can be done by yourself or in case the job is too big you can actually book your ETX 350 into a suitable mechanic.
Aprilia ETX 350 manual