For Hard back seat, you have to pop the hard back seat by unclipping the Top 2 clips. For Soft back seat, there should be a zipper.
anyway, you have open up the back of the seat and disconnect the active head rest connector.
Make sure you disconnect the battery post first, so u dont set off an airbag light.
press the release button on the left, and Stick a Small pick or screw driver to release a hidden button on the right.