Because I needed to know. So far I've found 4 alternatives.
The best method I've found is to take a hacksaw and make 4 cuts in a square around the flat end of the shell. You don't have to cut all the way through the shell, and in fact one of the cuts shouldn't be as deep as the other 3. Then lever off the resulting flap of shell (or hit the square with a hammer, but that's likely to be messy).
now tell me where do u find square coconuts
the one i got is round so how can i hit it on the flat end???