right^ the Bullseye, and other similar aftermarket alloy pulleys with sealed-cart-bearings, were thin compared to the plastic originals, most came with a bunch of SS washers you were to stack on both sides to center the pulley in the cage. I've never tried to press out/in bearings in a pulley since they usually oulast the teeth and replacing the whole pair is cheaper...I assume it can be done like any other pressed-in bearing, but maybe too fiddly given how thin the pulley is.