The Irvine slow-roll RV shower door is designed to be mounted directly to the finished shower opening rather than to the outer decorative trim. To install, first remove the existing accordion door and any old track or frame hardware. Then, mount the side pieces of the Irvine door to the inside vertical jamb surfaces of the shower opening. The top assembly should be mounted across the top of the finished opening, ensuring alignment with the shower-side frame rather than the outer wall paneling. Key to a successful installation is having flat, solid mounting surfaces on both vertical sides once the old hardware is removed. To confirm the door will fit your opening, measure the smallest inside width (wall-to-wall) and the inside height, and provide close-up photos of the left and right jamb surfaces with the old door open or removed. This information will help determine if the Irvine slow-roll door is the right fit for your RV shower framed opening.