[shadetree]

welcome to the forums, your right, it has a retaining clip that holds it on the pinion gear, just take a drift punch, and whack it out/off, it should pop out.

 

[shadetree]

so the cup should just pop right off if I clamp the cup in a vice and hit the pinion?

something like that. I would use a drift punch, and hit the ridge on the cup, out and off the pinion gear, that's how I would do it.