Hi there, I found this on a Jag forum, I had nothing on my data base here, I hope that it works for you.
I have removed them dozens of times. You just pull them firmly upwards and they will come out of their grips. There is nothing fancy about it, and nothing to hold down or push on -- just put your hands underneath it and pull hard. If you have the TV screens in your headrests though don't do that until you have disconnected them or you will rip the cables out! Putting them back is just reversed, but once you meet resistance don't push any further or you will force down the motorised assembly they grip into.
It will be easier to move the seats fully forward then recline the backrests and remove from the rear seats, otherwise you might bang them into your head lining.