Is the pin stripe tape or paint??
If it is tape, you can just peel it off and use adhesive cleaner that is safe for your paint.
If it is painted on, also you can use thinner that is safe for your paint, but will clean off the lacquer ( I think ) they use for painted pin stripes. But pleez check with a friendly bodyshop first to ensure you do not damage your paint.
I've been a striper for a while... email me with the specifics of your situation and I will give you the correct procedure to remove the stripes. I don't know if my email address shows up here or not, so it's [email protected]