I have helped chicks out of their shells a few times and they have always survived.
A few points, always make sure you thoroughly wash your hands first, make sure chick is kept warm while you are doing it, I use some warm water and cotton wool to moisten the shell then very slowly and carefully ease it away. Sorry if I am stating the obvious.
If this is happening though something is not right I expect the incubator is not humid enough. You could try adding more water next time.