If you choose to execute maintenance for your Suzuki Boulevard C90T then it is usually recommended to have a Workshop Manual for a guide just in case you need to know how to take out a certain part like the Drive Shaft and match it again the right way.
Suzuki Boulevard C90T Workshop Manuals gives you distinct diagnostic facts for the car so if something is wrong it can help you identify what the issue is and the way to fix it. After that you can analyse if this can be done yourself or in case the job is too big you are able to book your Boulevard C90T in with a nearby garage.
Suzuki Boulevard C90T manual