If you have to conduct maintenance to your Derbi Senda SM DRD then it will always be a good idea to possess a Workshop Manual to keep just for personal reference if you want to know proven methods to take out a particular part such as the Clutch and install it again the right way.
Derbi Senda SM DRD Workshop Manuals offers you targeted diagnostic details for the vehicle therefore if something is playing up it will help you determine what the situation is and some ways to resolve it. After that you can assess if you can do this yourself or in case the job is simply too big you can book your Senda SM DRD in with a decent friendly mechanic.
Derbi Senda SM DRD manual