I actually had my next door neighbor do it, as he is a painter at the local Dodge dealer. He has a very smooth putty knife (says some of his compadres use a plastic one - I would) that he drips a solvent on that attacks the adhesive but not the paint. Sorry I didn't note what brand it is, but a local body shop should be able to advise. Anyway, he dribbled solvent along the top of the letters, worked the blade behind the badges, a little more solvent, some pushing NO PRYING and they came off. About half the black rubber (I thought it was going to be double back tape) came off. He used a slow speed air driven wheel made of eraser material to peel 95% of the material off, them some of the solvent on a rag for the rest. We rubbed a polishing sealer on it and the faint 'shadow' that was there is history.
Unless you are inclined to do it yourself, I might walk into a body shop and ask ... . they might do it for a song or a sixpack. the results are great. .