There is a small button on both headrest posts where they connect to the seat itself. Just press both buttons in and slide the headrest up and out of the seat.
I see it mentioned there is two bottons to remove the front headrests, this is not exactly true(at least on the 2012 models). There is one button & a small hole you need to press a paperclip or punch into to release the headrest. The rear headrests are different, there is two buttons, one thats visible one that is hidden a bit lower in the seat fabric(on the opposite post).
I needed to remove the rear headrest since no one will ever be in the back seat & they were just blocking the rear visibility. I also(I don't recommend this for safety reasons) put the back smaller headrests on the front seats. Now on long drives with the passenger seat laid back I have a usable headrest, not that horrendous neck pain causing thing they put up front. Last drive we went on I had neck pain for 5 days from falling asleep for a couple hours.