Brian,

On the back of the seat take your thumbs and push deeply into the seat back just below where you feel the top metal frame and directly in line with the two points where the head rest mounts to the top of the seat. There are two plastic release tabs located here. They lock two metal rods which extend from the bottom of the head rest. I've found having an assistant pull up on the rest while I press in the two releases works best. It make take a bit to locate the release tabs but they are there. Just keep pushing in through the back upholstery until you feel them.

Once you know how these work it's a simple task to remove any 240 headrestraint.

Hope this is helpful to you.