If you want to carry out fixes to your Suzuki DR 125 S then it is usually recommended to have a Workshop Manual to use as personal reference in case you want to know techniques to remove a certain component such as the Door and fit it again adequately.
Suzuki DR 125 S Workshop Manuals will provide you with specified diagnostic wisdom on your automobile so if something is wrong it will help you determine what the problem is and the way to correct it. Then you are able to evaluate if you can do this on your own or in the event the job is just too big you could make a reservation for your DR 125 S into a suitable garage.
Suzuki DR 125 S manual