I would try a gentle wet Brillo bath, If you scrub really hard or for a long time, it can cut into the paint, so maybe test rub the chain side first. :|
Sometimes a heat gun works for that. It's likely the sun has faded the paint on the whole chain guard however and the paint under the sticker will have a different luster.
If that's the factory silkscreen some cleaner like Spray Nine will take that right off (Ask me and my Sting-Ray with a screenless guard how I know this... :roll: )
Also some fine compound should remove it. Sometimes with these screens you will get a little "shadowing" if the paint has faded a little over the years.
Carb Cleaner is the answer. I tried it with a brillo pad, and that did nothing but dull the paint and barely touched the lettering. But carb cleaner took it off in two wipes. Easy as you please.