How do I do a bent over triceps extension with alternating arms?

Bend forward at the hip about 45 degrees, holding a dumbbell in each hand, keeping your elbows bent 90-degrees, placed at your hip.  Keeping your back flat, extend one elbow until your arm is straight and parallel with the ground (perform a kick back).  Hold and then return the weight to the starting position.  Repeat with the opposite arm.