that's tricky without being there to see it in person. find a somewhat inconspicuous area and see if you can get a fingernail under it. if its a decal, you should be able to get under it and start peeling. just a word to the wise though, check all over the areas with decals. some paint shops will only paint to a body stripe instead of painting an entire panel like they should and replace the striping after a repair. make sure you don't have any crap work like that before you start peeling off decals. that will leave a really crappy line after removing the stripes that will only be able to be fixed with a respray.
best thing for removing any sticker, decal, or other undesired non painted crap off paint is an eraser wheel.
if the stripes are paint, your likely stuck with them