Do a search for 360 days for headrest. To remove them just insert a small nail or hex wrench in the holes where headrests go into seats. There is a small release inside, you will feel it depress, do one side at a time.
If you do the headrest search, you will find a mod to make headrest removal a very simple and toolless thing. Basically after you get the headrest out you will need to file the very last notch to a 45 degree angle like all the other notches. Very simple and effective.
The mod for the head rest, tooless removal, takes about ten minutes with a file. It is one of the handiest simple mods I have made. If you are tall and keep your seat back, it makes dropping the rear seat a cinch. Just pop out the rear headrests and store them under the front seat out of the way.