Outer pucks are impossible. Somehow, they completely made it so that the led burns out before the solder is even close to melting. The inner pucks are doable, not sure why it's different, but the inner pucks remove like AI Sols. Those royal blues on the outer pucks are a no go. If you have spare parts on another 1st gen hydra with inner pucks, transfer those over to your outer pucks and change the leds.