The first time I took them out, I pulled out the base on each seat. I freaked out a bit, and then just pushed it back into the seat. There is a second button on each head rest. Push it and pull hard...hahaha that's what she said!
I sat there rattling my brain and feeling like an idiot when I tried to remove mine. When you press down on the tab (on the right) it doesn't allow it to be removed. It only allows the headrest to move up or down to it's max height. You need to slide the other side of the plastic retainer. Clear as mud?