Start with your hands on the neutral handles. Set up like you're about to bench press. Bend your elbows and lay your hands back toward your shoulders. Bend your elbows and feel the tension build up in your triceps. Then punch and squeeze your hands to reverse the weight. You don't always have to bend your elbows until the bar is on your face, this variation shows that.
Do extensions until you can't anymore then move your hands into the angled handles and close grip press until you can't-do that anymore. Try to press the weight just by extending your tricep. Try not to use your pecs.
This is typically an accessory movement done on Max effort upper days. 3-6 x 6-12
The chains force you to lock your upper back into place more.