Take a hair dryer (or heat gun on LOW) and heat up the emblem (while it's not on your truck). You have to lightly bend the silver surround. You'll notice the center portion pulling up. Just carefully pry that off. Then, sand the blue off (without going inside the grooves that say FORD in silver). Repeat sanding until it is perfectly smooth. Mask off the front completely, and paint the back with the desired spray paint color. After it has tried, reattach the newly painted piece to the chrome surround with an adhesive that does not mess up the paint (I forget what I used). Then simply put it back on your truck. I still have my white one, it came out pretty good and wasn't too hard. I actually have it on the interior of my truck above my amp.
Here's the link to the RPS tech that I used way back when. However, I did clear the front of it.