How do you remove seat backs from a L bench on a pontoon?

I’m taking it in to be reupholstered so I need to take them out. The seats are screwed to the bases with hinges so that’s straight forward. I felt underneath and there seems to be maybe two bolts on the entire bench that come up through the bottom into the seat backs so there has to be more to it than that. Somebody said they are screwed in from the back of the railing on the outside of the boat but I don’t see any screws there either. Anybody have the answer? It’s got to be something simple I’m sure but I’m a rookie at all this.

As far as I know on pontoon seats like that there is only a few screws that go through the bottom of the seat to the floor and maybe a couple that go from the rail to the seat backs. Take those out and the whole seat will be removable. All the seats I’ve ever removed the seat back and seat bottom are not removable they are one piece.

There has got to be a way to get them off the plastic bases. Otherwise you wouldn’t be able to reupholster them. The seat bottoms flip up for storage and a live well on one end so you just unscrew them from the hinges.

Pull the seat cushions out and stick your head in. You’ll likely find a handful of screws that need to be removed.