If you choose to execute maintenance for your GAS GAS EC300 then it will always be a good plan to possess a Workshop Manual to use as a reference if perhaps you want to know how to remove a particular component including Drive Shaft and match it again correctly.
GAS GAS EC300 Workshop Manuals gives you exact diagnostic guides for the vehicle so if something is playing up it can help you determine what the problem is and the way to resolve it. You can then analyse if you can do this by yourself or in case the job is too big you could make a booking for your EC300 in with a nearby car garage.
GAS GAS EC300 manual