There are several ways of describing the push away. One thing that there is no argument about is that the left hand (right handed bowler, opposite for left handers) carries the weight of the ball from the setup until the ball falls into the swing. When your left hand releases the ball the ball should fall naturally into the swing. After the left hand releases the ball it should immediatly point left and go no higher than shoulder level. When the ball goes into the swing your arm remains straight through the delivery. You will notice I did not say the arm remains locked. If you lock the arm in a straight position you will create unwanted tension. Allow the arm to remain straight throughout the swing. Those two videos give you a good look at a proper setup, swing and push away.