Well, replaced seat this morning. Noticed beneath upholstery some sensors (??), and 3 connectors under seat (only 1 wire from seat itself; all 3 lead to front of auto). All it took was to disconnect wires, removed seat track, then seat itself. I could then have just replaced the upholstery (which is just hooked on, not sewn), but opted to replace entire cushion. And, hey, airbag didn't pop. Cost me 1/2hr of my time, rather than the $175 Hyundai wanted
Thanks again to those who responded to original post
Thanks again to those who responded to original post