Accually, when you have the barrel out, the rollers should look like they are falling out, but you should not be able to remove the rollers like that unless they are worn to the point of being unsafe. To remove them or replace them, you accually have to romove the roller cam(the sliding part that is under and around the barrel). To do this, you have to remove the pin you see in the side of the chamber block of the barrel. Once this pin is removed, you can slide the roller cam forward allowing the rollers to be removed. Once done, put rollers back into the slots, and slide the cam back into place, and replace the pin.