Removing seat covers

[niggtv]

Does anyone know how the seat back covers can be removed on the Vantage? I actually dont need to remove them totally, but the padding in the headrest has slipped down for some reason. They're the 2007 onwards design and I can see a zip if I look upwards at the headrest....presumably I need to find the start of this zip, unzip it, and then get a hand in!

I guess this is behind the solid seat back sections, but I'm not sure how these fit, and dont want to break it trying to remove it.

Sorry for slightly garbled question - not easy to explain!