If you want to perform maintenance to your KTM 250 EXC F then it is usually recommended to have a Workshop Manual to use as reference in case that you want to know the best ways to take out a particular part like the Wheel and install it again in the correct way.
KTM 250 EXC F Workshop Manuals are able to offer targeted diagnostic guidelines for your vehicle so if something is playing up it can help you discover what the situation is and how to repair it. After that you can decide if this can be achieved yourself or that the job is too big you are able to make a booking for your 250 EXC F right into a local friendly mechanic.
KTM 250 EXC F manual