If you choose to conduct fixes on your own Honda SH150i then it is always recommended to have a Workshop Manual to use as a reference should you need to know easy methods to take off a certain part much like the Brake Pads and match it again correctly.
Honda SH150i Workshop Manuals can offer you specific diagnostic info for the car so if something is playing up it will help you discover what the situation is and how to resolve it. Then you are able to evaluate if this can be done yourself or if ever the job is too big you can make a booking for your SH150i in with a suitable garage.
Honda SH150i manual