If you choose to conduct fixes for your GAS GAS TXT 125 Pro then it will always be a good idea to have access to a Workshop Manual to keep just for personal reference in the event that you want to know easy methods to strip off a particular part including Exhaust and fit it again appropriately.
GAS GAS TXT 125 Pro Workshop Manuals provides precise diagnostic guidelines on your vehicle so if something is faulty it will help you figure out what the problem is and some ways to repair it. You can then assess if this can be achieved by yourself or in the event the job is too big you can actually book your TXT 125 Pro in to a nearby garage.
GAS GAS TXT 125 Pro manual