Does anyone know how it’s even possible to install this replacement. I’ve been @this for hours. Screws won’t tighten. Blocked by inside center rail!

Thank you for your inquiry regarding this item from Prime-Line Products. Since you've got the instructions when you've purchased it, there is an image showing the installation. You may wish to contact Prime-Line directly and send photos of your issue. You can contact the manufacturer directly with your questions regarding this item, or any other product manufactured by Prime-Line Products by calling their toll free number at (877) 649-9740, or by contacting them by email at info@primeline.net.