To safely open a fresh coconut, you can either tap it gently with a hammer or crack the nut on a hard surface, such as a sidewalk. The first step is to remove the coconut water by piercing the softest of the three holes at the top.
Once you drain the water into a container, hit the nut while rotating it. After a while, the nut should break into halves. Another safe method is to wrap the coconut in one or two plastic bags and throw it against a garage floor until the nut breaks. This creates smaller pieces and does not involve a hammer.