Removing 100LL Fuel Stain

I have a composite airplane (a Dragonfly MK-IIH) and have a stain from 100LL
on the side of my fuselage that I would like to remove. On the way to
AirVenture this year I fueled up in the morning and left the aircraft parked
on the hot ramp for the rest of the day. When I returned the next morning I
had some very ugly blue streaks running down the side of my fuselage. I
thought I had left enough expansion space, but obviously I did not.

The stained area on the fuselage has a urethane foam core and the paint is
Emron. Any suggestions on how to remove the stain without destroying the
paint or foam core?

Thanks,
Jeff