They bolt on, according to the Haynes manual. Sure looks like it's designed to bolt on, too. The assembly is the entire hub and bearing. Spindle nut holds it on I think. I have one sitting on my table waiting for me to work up the nerve to attack the old one (also on the right passenger side, seems like the pass. side ones go out first. Had a front passenger bearing go out a few thou ago but the driver's side is still tight).
If you do the replacement, post back how it goes, please. I've been waiting on doing mine until I get some air tools to handle that spindle nut, (I remember the one on the front was bad even with an impact wrench), but I'm curious if there are any "gotchas" doing the job. | 
