When it comes to the hogrings, I just cut them with diagonal / wire cutters. Another list member mentioned this already. But here's what to do for reinstallation: skip the hogrings entirely and use zip ties instead. So long as you use quality zip ties you shouldn't have a problem. Get the ties nice and tight and trim off all of the excess. I've done this on several seats with no failures.

'85 Vanagon w/2.0 inline 4