dead easy....
fronts: locate the seat rails on the left and the right.... remove the plastic covers at the ends.
now look down the middle of the front seat (from the front), locate the square peg... it's spring loaded - compress it, then remove. seat should now come off if you push it back. that's the same procedure for both seats in front...
back even easier...
bottom cushions on back are just screwed down (torx screws i believe). top parts i have never removed but can't imagine it being difficult at all. most likely just bolted down as well...