You can also remove the backs from the couch by unscrewing where they attach to the base once you have moved the couch away from the hull. That makes it easier to remove if you are having it reupholstered
For the dinette you have to first remove the vinyl wall covering that's above to the right as you enter the guest state room. There are a few large screws that are accessible at this point. Remove them and then the seat back lifts up and out of clips holding it in place against the seat backing and hull.