What you need to do to perform an Up and Under is use the X button. Try kicking to an area that is close to the try zone and fairly empty. Also when kicking try to get the ball into the try zone so you don't get tackled from behind like I did several times. Once the ball is in the air hit the LT to change players and attempt jumping for the ball with B. It will take a few tries to time it but as long as you recover and the computer teammates don't, you should get the achievement. Let me know if you have any questions.