Step 2 should be: Put the side with the seed DOWN skin-side down, and lightly whack the long sharp edge of the knife into the seed without risking your hand. If you’re afraid of the avocado escaping, hold one end, but don’t put your whole palm directly in the line of cut. A lot of people wind up in the ER because avocado seeds are slippery and may send the blade askew, or just because they missed.