Have weight plates attached to only one side of the bar. Place the other end of the barbell against a wall or something like that.
Stand above the bar, with your feet to each side and about shoulder wide, bending your knees slightly. Bend forward at the waist keeping your back straight and grasp the V-bar. Rise your back and keep your torso almost parallel with the floor. 
Keeping your torso still and your shoulders close to your torso, pull the bar up as far as you can. Do not bend or straighten your legs.
Hold this position for a moment and slowly lower the bar back.