In the trunk, up top in the back is a cross bar. There are holes about the size of a nickel in the cross bar. Inside the holes are two little black switches. You will need a small flashlight and a hook tool. Flip the switches to the left with your hook tool. This will allow the rear seat to come forward about 1 1/2 feet. Just enough room to remove and re-install the headrest.
Hope this helps out.