This is an advanced exercise and modification of the basic squat. Mastery of the squat is recommended before attempting this exercise.
Place a barbell on your back, above your shoulders with a wide grip.
Cross the lower leg above the knee of your supporting leg (the leg you will squat with).
Squat down as low as you are able.
Slowly return to an upright position by straightening your hip and knee.
Switch legs and repeat.