I use to make these a lot and its not that hard really...
Chop the end off, (the size u want the hole) with a small saw... 
The rake out all the inside (i use to use a spoon to do this, or use anything that makes it easier for you)
The outside i use to srape all the hairy stuff off with a knife.
The soak the coconut in a bowl of boiling kettle water for 20 minutes.