I'm guessing you're talking about the dust washers.
They can be mounted iether OVER the CP artwork, or between it and the CP base, like what you've got.
If the artwork and plex is fixed down (which it probably is), I doubt there's any way to remove and replace those washers.
Best bet is to find replacement sticks with the right dia shaft.
Otherwise, you might be able to center the dustwashers, clamp them somehow and drill them out a little larger (they're just plastic, won't be hard to drill, just keeping them from spinning might be a pain).