Pick a nice ripe mango. It should feel heavy for it's size, be pleasantly soft and smell like mangoes near the stem.
hold the fruit on its end with the widest between your thumb and fingers and cut down on either side of the stem.
repeat with the other side.
holding one of the halves in the palm of your hand carefully cut a grid in the fruit but don't pierce the skin.
turn the half inside out so the fruit stick out in cubes. You can peel the cubes off with your hand or knife. Trim the remaining fruit off the seed.