Preheat oven to 375. Using your hammer and nails, poke a hole in each of the eyes of the coconut. If necessary, use the screwdriver to enlarge the holes. Drain out the milk, making sure it smells and tastes sweet. If the milk does not taste sweet, the coconut is inedible. Place in the oven and cook for 25 minute or until you hear a pop and it has cracked. Remove from the oven. Hit it with a hammer until it splits. Tap the shell with the hammer until the meat falls away from the shell.
If you need grated coconut, you can place the meat into a food processor and pulse until the desired texture is reached.
This sounds scary and dangerous but it’s really not. The skin pops right off after it’s heated without the coconut meat being affected taste or otherwise. Just make sure you use very clean nails and a clean screwdriver.