Headrest removal/adjustment?

I've got myself 3 front seats that have come to the end of their life as is. While i'm waiting for my re-trim kit to arrive im in the process of stripping them down and de-rusting the frames. As my defender has recaro seats ive no idea how to remove the headrests when they have been upholstered. There dosent seem to be any way of moving them up and down. With the covers off, i found a small clip which i pushed in and then hammered the headrest off. this is hidden when they are upholstered. Also there are 2 pairs of philips screws 3/4's of the way up the back, 2 on each side. it looks like there should be somthing else there but thats all i have. Any ideas as to what they are for or whats missing?
Cheers Mick