Bearings for Ichiba rear 5 lug hubs

[Def]

I've nuked 3 Z32 rear bearings(2 OEM, 1 Timken) in the past 4k miles in my car. No installation errors. But that's almost all track usage. I guess that means I don't drive like a douche.

So given that NSK Z32 rears are ~$140/ea, I think it'd be cheaper to just go with something I can actually replace the bearing. The Ichibas seem like one way to do this since people talk about replacing them often.

But how do you replace the rear bearings? What replacement bearing do they use?

The stock rears for S13s are not serviceable according to the FSM and looking on courtesyparts.com. So don't just say "they use OEM bearings."