I assume that the deck is seam taped to the hull inside and out. If so, then I would try to remove the outside seam and some of the inside seam by using a heat gun. Apply some heat to the end area of the tape until you are able to raise the edge of the seam tape with a putty knife or the tip of a utility knife. Once you have the edge up, grab it with a pair of pliers. Apply heat to the seam tape as you gently pull up on the end. Only pull as hard as needed to remove the tape with heat and don't heat so much that you heat up the layer of main glass too much. It takes some patience and practice to remove the glass, but it will come off. Once off where you can reach it, try getting a small saw between the two halves and cut through the rest where you can not reach with the heat gun. I have some info on stripping with heat and photos on my web site on the "how to" page under major repairs. http://www.orcaboats.ca