Pull the leg away from the body. Separate the leg by cutting through the skin, then following the contour of the leg with your knife. Once you've cut through the skin, bend the thigh joint back to pop the ball joint out of the socket. Once out, cut along the hip bone to remove the leg, ensuring you include the "oyster".
There are two "oysters" in a chicken. They are two small, round pieces of dark meat on the back, in a hollow area just above the thigh. The oyster meat is coveted by many for its flavour and texture.