You need to "cut" it off the top of the paint. If you polish it off you will also be polishing the surrounding paint the same amount, correct? That would NOT be good as you would go thru the clear about the same time you go thru the stripe. The stripe may cut faster being it is likely not a 2K cured paint as the clear is, but the clear would most certainly be cut as you are cutting the stripe.
So to remove the stripe your first plan of attack would be simply rubbing it off with a rag with lacquer thinning on it. The stripe is often simply enamel striping paint that will wash off with lacquer thinner. After washing it off you then polish the clear to remove any texture difference or remnants of the stripe.
Another minimally abrasive method may be a clay bar. I have been amazed at what this very interesting tool will remove. You can pick one up at a paint store, Magic clay is a brand name but there are others.
Clay Magic Clay Bar - Blue Fine Grade, CM-2200 - Detailing.com
This clay wipes off anything "stuck" on a smooth surface. I have used it to get direct overspray off a plexi-glass window with no damage what so ever to the window, how about cured urethane primer overspray off a car, again, totally removed it with no damage what so ever. No cutting, no wearing of the clear like polish or compound would do, it really works well and may take it off, I have never tried it with a painted on pin stripe but I wouldn't be surprised if it took it right off.
The next step after those fail would be to sand it off. Using very fine color sanding paper like 1500 with a block, a narrow block and carefully sand only the stripe so the surrounding clear isn't sanded. You can do this with a block because the block is going to hit only what is highest, unlike the polish compound that is cutting everything, that is the difference and a BIG difference. If you are careful you can cut just the stripe off with very little effect to the surrounding area and then polish the clear back to a shine.