Yay yay yay! That's fantastic! What a cutie!
I usually leave them in the incubator only until they are completely dried out and/or coordinated, but I make a point of opening the incubator only twice a day. So in the evening, I remove any ducklings that are dried out, and then again the next morning, etc. I find that leaving them in the incubator for long periods often leads to more trouble than its worth, especially when the eggs are lying on their sides. They just mess with the other eggs too much, and also with the fan & heating element & so on.
Congrats!