The proper way is to use a heat gun or hair-dryer. SLOWLY heat the emblem and as the glue softens, you should be able to pry it off. Use a rag against the paint, and a flat screw-driver to gently pry as you heat it. Maybe use a hair-dryer 'cos those heat guns get pretty darn hot and you may melt the damn thing! Use 'goo-gone' to remove any glue residue...