Assume a shoulder-width stance, with knees inside the arms.
While keeping the back flat, bend at the knees and hips so that you can grab the bar with the arms fully extended and a mixed grip that is slightly wider than shoulder width. The bar should be close to the shins with the shoulders over or slightly ahead of the bar. This will be your starting position.
Extend the knees to raise the weight, keeping the angle of the back constant. Continue to lift the bar straight up, while keeping it close to your body.
As the bar passes the knee, extend at the ankles, knees, and hips forcefully similar to a jumping motion. As you do so, continue to guide to bar with your hands, shrugging your shoulders and using the momentum from your movement to pull the bar as high as possible. The bar should travel close to your body, and you should keep your elbows out.
At maximum elevation lean back and rest the bar on your torso. Switch your grip to a double overhand, and hitch the weight onto the front of the shoulders. Without moving your feet, press the bar overhead by extending the elbows.