In my experience, it takes a hE*& of a lot to crush the sleeve, if you hammered on it with a big gun, you might get it to move, but not if you just cranked down the nut. When a new sleeve was installed, i had a hardtime getting the sleeve to crush to get the pinion turning torque right. JMO but i would gun it till the nut stops turning and let off. Then like said before, just stake the nut with a chisel and hammer in a couple spots. A major teardown seems a little much for just a seal replacment.