I have made repairs around the main winches, the genoa tracks and the cabin top. Those areas used 3/4" balsa. I had to make the repairs from the top around the main winches because there is a layer of plywood under the balsa that gets in the way. If your deck looks good and you don't plan on repainting, I would try to make the repairs from the underside. When you are ready to start the repairs empty the boat of everthing before you start cutting. You don't want the fiberglass dust in you cushions or sail bags, and cover everthing with plastic. believe me, the epoxy will somehow get everywhere.
