If you want to execute maintenance to your KTM 50 SX Junior then it will always be a good idea to own a Workshop Manual for a reference if perhaps you need to know simple methods to take out a certain part for example, the Wheel and fit it again properly.
KTM 50 SX Junior Workshop Manuals provides specified diagnostic guidelines for your vehicle so if something is faulty it will help you discover what the problem is and the way to correct it. After that you can analyse if this can be achieved yourself or that the job is just too big you could book your 50 SX Junior in with a nearby mechanic.
KTM 50 SX Junior manual