I talked to a body shop buddy of min here in Seattle, and he said that there is a chemical that they spray on the decals, emblems and trim to remove them. I bet that if you go into any body shop and ask them for the name of whatever they use, they'll tell you. I can tell you from experience if you have an older truck with a color that has faded from the sun, that when you take the emblems or trim off the paint underneath will be a different color, i took the trim pieces off my Silver truck, and the paint was noticeably different, enough to make me wish I would have left the trim on. Hope this helps,
-kevin