If you want to accomplish adjustments on your Derbi Mulhacen 125 then it is usually a great idea to have access to a Workshop Manual for a reference in the event that you want to know the best ways to remove a specific component for example the Wheel and match it again accurately.
Derbi Mulhacen 125 Workshop Manuals provides special diagnostic guides for your vehicle so if something is playing up it helps you identify what the issue is and ways to resolve it. You will be able to evaluate if this can be achieved by yourself or in the event the job is just too big you could make a booking for your Mulhacen 125 in to a local mechanic.
Derbi Mulhacen 125 manual