This exercise is best performed inside a squat rack for safety purposes.
Set the bar on a rack to just below shoulder level. Step under the bar so that the weight sits on the back of your shoulders, slightly below the neck
Lift the bar off the rack by pushing up with your legs and straightening your upper body.
Step away from the rack and position your legs shoulder width apart with the toes slightly pointed out. Keep your posture straight and you head up
Inhale and begin to slowly lower the bar by bending the knees. Continue down until the angle between the upper leg and the calves becomes slightly less than 90-degrees. Be sure that your knees do not pass over the front of your toes. Keep your head and chest up and core engaged
Exhale and begin to raise the bar back to starting position by pushing through the heels as you straighten the legs