To extract the arils from the pomegranate, slice the fruit in half through the middle (as you would an orange). Then, taking one half and holding it cut-side down over a high sided bowl, take a heavy metal or wooden spoon (or similar) and whack the side of the fruit a few times to release the arils. Work your way around the fruit until most of the arils have been released. For any stubborn pockets of arils, simply take the fruit and turn it inside out, fishing out the remaining arils. Discard the bitter pith.