in my opinion its easier to pull the seats out first. 4 bolts hold it to the car, one in each corner. then lean it over and disconnect all the wires and bamo, comes right out.
after that, theres various screws holding the plastic trim, it's not hard at all, and that way you can work the seat cover on better.
mind linking me to what covers you got? I got some but not sure if i really like them.