If you need to do maintenance tasks on your own Rieju NKD 125 then it is usually recommended to have access to a Workshop Manual to keep just for personal reference if perhaps you need to know the best way to remove a particular part like the Dashboard and fit it again correctly.
Rieju NKD 125 Workshop Manuals offer you certain diagnostic guidelines on your vehicle so if something is wrong it can help you determine what the situation is and tips to resolve it. You can then analyse if this can be done on your own or in case the job is too big you are able to book your NKD 125 in to a local mechanic.
Rieju NKD 125 manual