The way to tell if you have an early or late 49 is by this strip which fits around the inside of the glovebox. I am guessing you need the later version. Seperate from that they do require some push/pull effort. I found the best way is to get the top edge in place, you can then get your hand on the back to pull it down. Good luck!
https://www.flickr.com/photos/advance-design_parts_co/14584820638/in/album-72157631868452754/
https://www.flickr.com/photos/advance-design_parts_co/14584754750/in/album-72157631868452754/