Drain the pool.
Grasp the sledgehammer halfway down the handle. Make sure that you have a tight grip on it and that your hands are positioned on the handle in such a way that you can control the movements of the sledgehammer, yet can get enough power in each swing to break the concrete.
Whack the top of the concrete edging with the sledgehammer until it cracks. Work your way around the pool breaking up the concrete. Put down the sledgehammer.
Put on the gloves to protect your hands while handling concrete fragments. Pick up loose with your hands and discard. Wedge the crowbar underneath stubborn chunks to dislodge them. Continue until all of the concrete pool edging has been removed.