In my book Stir, Laugh, Repeat, I have a recipe called Pina Colada Cake (page 146), in which I use fresh coconut.  When I make this cake I always end up with the same question "How do you get the coconut out of the shell?" 

First you punch holes in the "eyes."  These are easy to find and there are 3 of them.  I use a clean nail and hammer to punch the holes and then drain the "milk."  When I was a kid I loved drinking the coconut milk and still do.  After draining, wrap the coconut in an old towel, one you don't plan on using again.  Take it outside where there is a hard surface, hopefully concrete.  Hit it hard with the hammer.  Be careful, sometimes it goes shooting across the parking lot or whereever you might be.  Keep hitting until you have pieces no bigger than maybe 4".  Next, take a blunt knife and press it under the edge of the coconut and shell to loosen the pieces.  They will usually pop off the shell fairly easily.   Now you will see a brown "crust" still attached to the coconut.  This has to come off.  I do this with a knife but please be careful and don't cut yourself.  If you follow these directions carefully, you can enjoy fresh coconut.  After all of this is finished, you can chop or shred your coconut.

Or you can do what I do 99% of the time which is go to the grocery store and buy a bag of already shredded coconut.