To defrost the phyllo, leave the unopened package in the refrigerator overnight and it will be ready to use the next day. Do NOT thaw at room temperature because the sheets then have a tendency to stick to each other. One of the difficulties of working with phyllo is that it tends to dry out very quickly once exposed to air. Thus SPEED is of the essence. Before unrolling the phyllo, make sure that you have a large area to work on and that ALL your ingredients and utensils are at hand: baking pans, a pastry brush, the filling, wax paper on counter, and, most important, the melted, but not browned, butter that will be used to top each individual sheet. If you are going to bake the phyllo pastry immediately, your oven should be preheated.