If you need to accomplish auto repairs for your Derbi xRace 50 SM then it is usually recommended to possess a Workshop Manual to use as personal reference should you need to know the way to strip off a particular part much like the Door and match it again in the correct way.
Derbi xRace 50 SM Workshop Manuals can offer you exact diagnostic details with regards to your vehicle therefore if something is broken it can help you figure out what the situation is and how to repair it. You can then determine if this can be achieved on your own or if ever the job is simply too big you are able to book your xRace 50 SM in to a decent mechanic.
Derbi xRace 50 SM manual