You'd probably have to wait until the next mod election (if there is one), and then join it. If you get enough votes in that one, you'll become a mod (though there's no guarantee that there's gonna be another election)
Well, they gotta break the rules first. Just being an anti-fur isn't good reason to ban. If I just started random-banning anyone who seems like an anti-fur, then I'd probably lose my role as a mod.