A gang spray painted "dsor" in big black letters on my peach colored house and I need to find a way to get it off withougt ruining the paint. Is this possible?

Likely not. Spray paint dries quick. Try paint thinner but anything "hotter" will attack your house paint. What is your exterior material?

There are a few products, but if it has fully dried and is on other painted service, no, going to have to re-paint over it.