How can you safely remove Styrofoam from an oil painting?

I had the same problem with an expensive piece of Louis Vuitton luggage. A piece of styrofoam sheeting, which was in the LV storage box, had actually bonded to the luggage. After trying many mild cleaning solutions, my gorgeous and talented husband was able to lift the entire boo-boo off the luggage with a pair of tweezers.

Hope this helps,

David