Hi there! Welcome to the thread.
It's always a pain in the neck to remove the headrests! Actually there's a "push-in" button just beneath the plastic base of the headrest slots; they are positioned at the rear of each slot.
You'll have to feel them first by deeply (and frustratingly!) pushing that part which will feel like a sliding motion. Once you get the feel of it, push up and out the headrests which should slide upwards smoothly.
My thumbs ache everytime I change my seatcovers

Means "Sedan" in japan... Sakanila yung civic na 1997 may ferio sa ilalim nang civic na logo at...
Civic horsepower