You install the hardware right after you glue the heavy interfacing ("Stiff Stuff") onto the cork. I have a rotary hole punch for leather so I used that to make the little holes (You could use sharp tipped scissors), then you stick the prongs through, put the washer on the back and bend the prongs. The rivets work the same except you have to hammer the rivets on and you can do them whenever. I also add glue to the rivets just before I hammer them closed.
Watson