Found 2 screws at bottom of seat back but can’t find ones on top.
are they at the back side? The convertible has body brace about 6″ below the top of seat back are the screws attached to this?
The ones I have messed with had little bendable metal straps at the bottom. You have to bend them up first. Then pull out on the bottom just a little to clear the strap and then push UP with a good jerk. After both sides pop up then it should come right out. It sits on two hooks at the top and has to be lifted off the hooks but sometimes it requires a good jerk or bump to get it to lift.
From what I remember recently, I had two long arse screws on the top/back side of the seats. both sides. Stick your head back there and you should see them from the well side. it made no sense to me at first but I removed them and was able to pop the seat up and out.