If you want to do fixes on your own Husqvarna SM 50 S then it will always be a great idea to possess a Workshop Manual to keep just for reference in case that you want to know how to strip off a certain part such as the Drive Shaft and install it again effectively.
Husqvarna SM 50 S Workshop Manuals gives you specific diagnostic details on your car therefore if something is faulty it will help you determine what the situation is and tips to repair it. You can then analyse if this can be achieved on your own or that the job is just too big you can make a reservation for your SM 50 S into a local car garage.
Husqvarna SM 50 S manual