If you are talking about the bottom section it sounds like you are either missing the retainers in the floor or your seat is just not catching them. crouch down on the floor and have a look. I would attach a pic.but I am at work.If you lift the seat bottom up and look undr you will see what I am talking about if they are there( maybe someone cut them off,Is it the original floor?) If they are there then you have to push quite hard on your seat to "push it back,tilt it at a 45 degree angle first,then while pushing back,also push down. You are thrying to get the wire of the seat spring to catch on the hook.
Let me know if you need a pick and I can get you one later.