If you have to conduct repairs on your own Yamaha WR250F then it is usually a good plan to have access to a Workshop Manual to use as reference in the event you want to know the right way to remove a certain component such as the Clutch and match it again adequately.
Yamaha WR250F Workshop Manuals gives you exact diagnostic facts for the car so if something is broken it can help you figure out what the situation is and some ways to make it better. After that you can assess if this can be achieved by yourself or if ever the job is just too big you can actually book your WR250F in with a local friendly mechanic.
Yamaha WR250F manual