We often get the missionaries to husk one for us using a machete, which also works well but has the inherent risk of losing a hand or a foot... depending on which you use to hold the coconut in place while you chop it to pieces with the machete.
In this series of photographs, Alfred Nam demonstrates how to do it with a screwdriver... it takes longer, and more muscle power but it shows that it can be done. It has the inherent risk of breaking into buckets of sweat as you wrestle with these things.
Beginning to see results
This is the part where I break into a sweat.
Ok..now we still need to get to the actual coconut
ah... the machete comes in here!