Take a common hand saw and fasten two pieces of wood on either side of the blade so that the saw can only cut to a certain depth

Adjust that depth so that it is the same as the thickness of the cacao pod shell.

start your cut at the stem at a 45 degree angle.  The cut will naturally end up as a circle like the equator of the earth.

Break the pod in half, exposing half the 'nibs', still attached to the inner stem.

Peel back the cut part of the shell to where you began the cut at the stem.  This will expose the inner stem where it meets the shell.

Cut the inner stem at that point and all the nibs will fall out undamaged.

Estimated time   8 - 10 seconds.