Our son or one of his friends accidentally reversed the middle row headrests, and like others, I couldn't release them. After reading this thread, I found a fairly simple solution.
1) Insert a slot (flat head) screwdriver just barely under the plastic cover surrounding the post that does NOT have the push button, which is on the OTHER post. If 12 o'clock is directly behind the post as you sit in the seat, facing backwards, then insert the screwdriver at 9 o'clock. See picture for example.
2) Lift the plastic cover just enough to insert your screwdriver further in, pushing a hidden button that is under the plastic cover. You'll feel it give.
3) Let go of the screwdriver. The padding on the seat and the downward pressure of the plastic cover will sandwich the screwdriver in place. There is NO NEED TO REMOVE the plastic cover.
4) Push the lock button on the post that doesn't have the screwdriver and the headrest will lift right out.
I've attached a picture. The screwdriver is locked in place, pushing the hidden button. I love my Telluride, but I hope Kia fixes this obvious design flaw in the next model.
