I have a set of S4 seats I want to install into my 2015 allroad, but am having a tough time removing the rear seat backs. Can't find anything of a DIY. I can remove the clip in the center of the 60/40 split, but neither side will slide off of the pin on the outsides. There doesn't seem to be any latch or anything on the seat back either. Has anyone removed these? Any tip on what I am missing?