How to remove/change the fuel filler lock barrel over

[adventuredon]

Hi, looked but cannot find. My RepRom also only shows fuel filler cap removal as a whole. So will ask here..My fuel filler cap is playing up and does not want to lock when I try close it. It seems the lip it needs to connect under is a bit worn and sometimes it locks, then later pops open while I am riding. So have ordered a spare fuel ring and cap from motorworks . Now all I need to do is swap my fuel cap locking barrel over to the new one when it arrives. Anyone know how to do this? Or a link please?
Obliged
Don

 

[adventuredon]

Ok, no need. Took cap off and cleaned it all a treat. Seems to be catching better. If it fails again, will re open thread