Stand under the pulley and grasp the bar using a pronated (overhand) grip.
Flex your hips and lean forward until your arms are positioned by your ears.
Keeping your arms slightly flexed, exhale as you pull the bar downward and backward in a semicircular motion toward your thighs.
Hold for a count of two and squeeze your back muscles.
Inhale as you slowly reverse the motion and return the bar to the starting position.
Comments and tips
Keep your elbows slightly flexed and your body still. Only your arms should move.
When lifting heavy, for better balance, stagger your stance.
Instead of a straight bar, you can use either a rope attachment or a v-bar. You can also perform the cable straight-arm pull-down unilaterally (with one arm at a time) by using a stirrup (handle). Alternate between unilateral and bilateral training to derive the benefits of both.