I hate to admit that I cant find them in the parts catalog either. I put in a request to Ford, if they come back with a good part number I will post it here for you.
I just joined so i could reply, let me figure out how to post pics and I will do that.
As far as replacing them: Along the back edge nearest the door is a thin strip of double sided tape, and the top and front edge are held onto the truck with clips.
Get a good non-marring pry tool and start...