Provided there is no clearcoat on the frame a gentle solvent based nail polish remover and a plastic scourer should remove the decal without damaging the paintwork.

Let the liquid soak in to the decal for a minute or so and then gently wipe away the now broken up decal. When you see the colour of the decal fade like a watercolour generally thats when its time to start wiping.

Then degreaser and a damp cloth should clean up any remaining residue.

I would personally avoid razor blades or plastic knifes etc due to the risk of digging to deep, respectfully.