Install the plastic seat back and then install the bezels for the shoulder belt and the release button. Be very conservative in the amount of material you trim for the button and the belt; it's far better to trim and try a few times than cut beyond the bezels. Make sure you slide the release strip into the seat back and install the hinge screws. To prevent the hinge screw from working loose, install a jam nut against the weld nut. Fold the seats forward a few times and check the release.