Was inspired to try this today myself, since work is a little slow, working at a body shop I had everything I would need.
Pulled the emblems off with a stiff putty knife. Removed the sticky tape with my finger for the most part then used Wax and Grease remover to get the rest, cleaned that off with soap and water. Scoffed the emblems with a Scotchbrite to promote adhesion. Sprayed them with 2 coats of Plas-Stick adhesion promoter. Then sprayed them with 3 coats of Flat Black. Removed the tape off of the truck with a rubber wheel and cleaned surface with Wax and Grease remover. Reapplied the double sticky tape to the emblems and cut to fit. (Reapply the tape befor painting so as to not leave fingerpaints in fresh paint) Was going to spray with Clearcoat to protect the blackpaint but I didn't honestly want them shiny but you could do that.