I've used a hair dryer on high and rubbing alcohol, others have used a heat gun, be careful about staying in one place too long, and a 3M adhesive removal product. Seems to be a lot of ways but it takes time to do it right.
actually it's not that uncommon. I ditched mine for reverse c strips.I am thinking about taking them off so it will give the car a cleaner look. Plus I might want racing stripes sometime soon so it would look awkward having both.