If you wish to conduct fixes on your own Yamaha DT 50 MX then it will always be a great idea to have access to a Workshop Manual to keep just for personal reference should you need to know how to remove a specific part including Brake Discs and install it again appropriately.
Yamaha DT 50 MX Workshop Manuals offers you certain diagnostic guidelines for your vehicle therefore if something is playing up it helps you find out what the issue is and how you can resolve it. You can then analyse if this can be done on your own or that the job is just too big it is possible to make a booking for your DT 50 MX into a trusted friendly mechanic.
Yamaha DT 50 MX manual