Unless you know what you're doing, don't.
I have found a paper on 'safety holes'… very interesting.
One could argue that chicks that are not strong enough to get out of the egg by themselves should not survive. I have a different opinion.
To me all life is precious. So if I can save a chick by helping it, I will.
The 'safety holes' are used when incubating rear and endangered bird species. It increases the chances of survival in the fiercely process of hatching.
Yet one has to be extremely careful. It happens easily that a chick get's injured.
This video is about the hatching of my emu eggs, the second largest eggs in the world. (and the most beautiful ones :)
The first Emu chick got out all by himself. The second one needed a little help.