I've seen a lot of people using these:
http://www.ebay.co.uk/itm/Automotive-Toffee-Whizzy-Stripe-Removal-Wheel-/350329202253
...or stick a bump-strip over it?
Best bet if its too bad to live with, find some new/ scrappy bump-strips or come up with some graffix. And don't try sanding back will not go just get worse.
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