There's no easy way unless you pay to have it done. IMHO, the best way to do it yourself is to use paint
stripper that is specifically designed for use on fiberglass. Interlux makes it, but you can also get it from a specialty store that sells supplies to auto painters and body shops. They use it for fiberglass-bodied cars, such as Corvettes and customs. Don't use ordinary paint
stripper, such as for your house.
Brush it on with about a 4" brush, and when it starts to dry, brush another coat on right over it. After about 3 applications, try scraping a small spot. If most of it doesn't scrape off over a wide area, keep applying more coats. They key is to put it on, keep it wet, and let it work until it softens the paint
. It'll take longer to soften barrier coat. Eventually, it'll soften the paint
, and it'll be reasonably easy to scrape it off. Put a tarp under it to catch it, and then toss the tarp.
Wear long pants and a long-sleeved shirt and goggles, and wipe it off your skin if it gets on you. It stings.