Take a shoulder-width stance. Grab the V-bar, step back from the pulley, slightly bend forward and flexyour arms at the elbows to about 80 degrees. Keep your elbows close to your torso.
From the starting position do the extension (contracting triceps), guiding your arms to a full stretch along the body. Your wrists are firm throughout the motion. Inhale while returning to the starting position in the same way. Exhale along with the extension. Keep your torso in a fixed position throughout the entire motion. Do the required number of repetitions.
Keep your torso straight and do not bend at the waist. Keep your elbows in a fixed position without excessive sideways movement throughout the entire motion.
Choose an appropriate resistance to start with to master the technique well. If possible, exercise in front of a mirror toget the correct starting position and watch the entire motion.