If you want to undertake maintenance tasks to your Honda CRF150F then it is always a good idea to have a Workshop Manual to use as a guide in the event that you need to know the best way to take off a specific component for example Drive Shaft and fit it again properly.
Honda CRF150F Workshop Manuals gives you detailed diagnostic information for your vehicle so if something is not working it can help you discover what the issue is and tips on how to correct it. You will be able to analyse if you can do this on your own or in the event the job is simply too big you can still book your CRF150F into a suitable mechanic.
Honda CRF150F manual