in incubator keep it at where it was for incubating. 99.5f for forced air, and 102F for still air.
after they're dry and in the brooder around 95F will be high enough.
to keep humidity up, it really depends on your incubator, but generally try not to open it so the humidity doesn't escape. add water as needed to keep it where it is.
there really isn't much to be done to keep the temp and humidity stable if you're opening the incubator to assist. try to be as hands off as possible. but if you do choose to help them try to keep the opening as small as possible even draping a damp hand towel over where the incubator will open will help keep the heat and humidity in while you are opening it.
if you are assisting, take the egg out of the incubator while you're working on it. you'll need to be able to see what you're doing clearly, and have full control of your hands. Also you don't want to risk any other eggs in the incubator having problems because of the dropping humidity.
could you post a picture of the hole it's been working on?
Usually a chick will pip externally, sit there for what feels like forever then make a second pip and fall asleep for hours and hours before deciding to actually zip. I've heard that ducks usually take 48 hours from external pip to zip.