Stand perpendicular to the bar so the bar is off to your side. Grab the collar end of the bar and lean forward. Be sure to keep your back flat. Keep your elbow out wide and pull your elbow up by squeezing your back muscles. Slowly straighten your arm out and repeat for 6-12 reps. Repeat on the other arm.
This is a great variation to the dumbbell row and really places a different kind of stress on the back muscles and rear delts.