With a large nail and hammer, puncture the eyes of the coconut. Place upside down in a large strainer and drain into a large measuring cup or medium bowl. (Reserve juice for another use.) Open the shell by hitting firmly with a hammer around widest part of the coconut. Use a small sharp knife to pry out coconut meat and peel off the brown skin. With a vegetable peeler, slice coconut meat into strips.
Preheat oven to 350° F. Melt butter or margarine in a 15 1/2 x 10 1/2 x 1-inch jelly roll pan. Remove from oven and spread coconut slices evenly in the pan. Bake for 10 minutes; toss and bake 6 to 8 minutes longer or until crisped and golden brown. Remove from oven and drain on paper towels. Blot top of coconut with another paper towel to absorb as much grease as possible. Sprinkle lightly with salt. When cool, store loosely covered in a cool place.