Heatgun, (blow dryers are not hot enough) and wooded, plastic scraper with an sharp edge or butter knife (without cutting edge) will help lift it once it is hot enough.
Commercial decal glue remover or Goof Off on the residue. I used paper towels soaked in Laq thinner, worked well. decal removing
I used a heat gun and it worked well. Be careful not to use too much heat. I scraped it off with a metal scraper, being extra careful not to scratch the gellcoat. I removed the residue with acetone.
Most bodyshops will also carry a gum eraser type bit that fits into an electric drill.
We have used these on aluminum panel trucks with excellent success. The rubber shouldn't be able to rub through the gel coat, but as always, start slow.
