Take the backing off the memory box and lay out all your items on it so you can get them set up the way you want it.
Heat your hot glue gun. Once it is hot, start attaching the items to the background with the glue.
After everything is in place, put the cover on and secure the backing to the frame. I would wait a few minutes before hanging it on your wall to be sure everything has had a chance to dry.
Decide where you want to hang your memory box and hammer a nail into the wall and hang your memory box. Enjoy!