The big thing on this one is to keep your body in a straight line. Squeeze your glutes hard to keep your hips up. The rowing portion is like Amy other row, shoulder blades together and drive your elbows back. Row to the front where you want to train the back. If you want to train lower back on the bar to your belly if you want to train upper back row the bar to your chest. Simply adjust your positioning under the bar to hits these spots.
An easier variation is to have your knees bend and feet flat on the floor and maintain a straight line from your knee to shoulder instead of ankle to shoulder. To make them hard you could do these out of blast straps. You could also add weight to them by draping chain over your stomach or running a band over your stomach.
Set the bar about hip height. Sets and reps can be 3-6 x 6-30. We usually just did them to failure. Just make them difficult.