Do you mean the Sleeve? If so the easiest way to remove is to leave the flywheel on then take a medium sized zip tie place it threw the exhaust port and turn the flywheel. The piston will hit the sleeve and if you keep turning it should push up the sleeve and you should be able to remove it by hand, pulling upward. Make sure to try to pull it evenly as possible. This does get more difficult with the more gallons you put on them in most cases.