I'm putting together a 'How To' for heating the driver and outer passenger seats at the moment. In the course of that, I've removed them and stripped the upholstery from those two seats, but I didn't touch the centre seat. At a casual glance, it doesn't look a whole lot different to the other seats in the way it goes together.
I've got some photos that probably show enough detail to get you on your way. I'm currently very busy on work and I'll be off to work abroad for a couple of weeks on Saturday, but if I get time I'll upload the relevant pics before I go.