Put it inside a bead blaster with the softest media you can find and work from at least 12" away to start out. Walnut shells may be a bit harsh, but they make some very tiny glass beads that may work if you turn the pressure down a bit.

Don't use sand!! That will blow holes in fiberglass in about 1/2 second!! Guess how I discovered that little jewel of information?[sm=lol.gif] [sm=red_smile.gif]