Do you know that a coconut has eyes? It has a face. To open it without tools like a drill or a saw you need to get to know it better :)

I'll give you some hints. To open a coconut you will have to look at it more carefully and you will see two similar dots - these are eyes and  the other one  is a bit odd shaped - mouth. Take a knife, open it's mouth and get the water. Now it's gonna bit a bit harder. If you split the eyes and follow it straight up the back, you will see a hard ridge line. Stop right in the centre and start hitting. In my case I had to use a lot of power ;) Maybe I didn't get in with my coconut ;) When I improve my technique I'll let you know.