The front seats are both held in with body posts.
If it's the bottom cushion, just get something long and flat under it... and pry it up.
If it's the backrest... you pull the body posts out from the bottom, and then lift up.
The backrest has 2 plastic body pins, and 2 aluminum pegs. (that's why you lift it up, after pulling it out)
FYI... you will probably need new pins once it's pulled apart. (get them at an auto parts store)