I have stripped and restored an old stripper canoe with this method. As you begin to release the fiberglass from the gunnels, cut it int 2 inch strips and slowly peel the strip as you would open a sardine can. Just roll the small strip to the keel. Use a sharpened piece of maple or oak as a wedge and pry the glass off the hull. This method will keep the wood splinters from tearing a large hole into the hull. It allows you to have more control than just ripping the glass off the hull.
Use a heat gun if required but with this method I found that there was very little tearout and the final result was easier to repair. Hope this helps. Erich