Sit on your hands! Leave those eggs alone... it can take up to 72 hours for ducklings to hatch, once they have pipped. They take their time, and they do a lot of resting inbetween efforts to zip their shells. They are also absorbing their yolk sacs, the veining and blood is being absorbed. You open that membrane and damage the veining before it's absorbed, and you can cause the duckling to bleed to death. Everything is proceeding normally, and you just need to keep your hands out of the incubator, and off those eggs. You keep opening the incubator, you drop the humidity, and this is the critical time, because their digestive system is finishing up developing during these last few hours. You will also cause them to shrink-wrap, and they won't be able to hatch, but die.
Go read the Hatching Eggs 101, and the accompanying "Assisting Hatching Eggs" articles, multiple times, if you have to, to find out more about what goes on during these last few hours. This is the most critical time, and the hardest to have the most patience. Good luck with your hatch!