If you choose to perform fixes to your Derbi Supermotard DRD then it is usually recommended to have a Workshop Manual for personal reference just in case you need to know how you can strip off a specific part for example, the Door and match it again the right way.
Derbi Supermotard DRD Workshop Manuals will give you targeted diagnostic wisdom on your automobile therefore if something is broken it helps you ascertain what the situation is and tips on how to fix it. You will be able to assess if this can be achieved by yourself or if the job is too big you can actually make a reservation for your Supermotard DRD in to a trusted repair garage.
Derbi Supermotard DRD manual