Preheat oven to 350 degrees. Test each of the three eyes at the stem end of the coconut to find the softest eye. Use an ice pick and a hammer to pierce the eye, then drain the juice into a glass through a fine sieve, and reserve for another use.
Tap the coconut with a hammer until a palm-size piece of the shell breaks off. Continue tapping around the broken edge of the shell until it begins to break apart. Place the broken shells on a baking sheet. Bake the shells for about 10 minutes to loosen the coconut flesh from the shell.
Remove the coconut shells from the oven, and allow them to cool to the touch. Pry out the meat with an oyster knife. With a potato peeler, remove any remaining brown skin from meat. Grate the coconut meat, or slice it with a mandoline.
Preheat oven to 350 degrees. Place grated or sliced coconut on a baking sheet and transfer to oven. Bake until lightly toasted. Let cool before using.