There are two things that you have to push in to release the seat. If you are sitting in the seat the button you push is approx. right between your legs up under the seat. (One on both sides of the car). You will have to run your hands up under there to find exactly where it's at and you will probably have to take a screwdriver or something of that nature and slide in there to push the button. Push it in and pull up on the seat and it should pop right out. Good luck!
There are 2 releases under the seat cusion. They are about the middle of each passenger location. Take a flathead screwdriver with the blade horizontal ( like this - ) and run it under the bottom of the cusion to locate the releases. When you hit the side of the release pull the screwdriver out far enough to get in front of it (but not out from under the seat cusion), slide the screwdriver over about 1/2" to 3/4", turn the screwdriver 90 degrees ( like this ! ) and push forward. This should push in the spring clip and release the seat. There are two of these releases, one on each side. Hope this was clear enough.