This is the part of hatching that a lot of novice hatchers are worried about. What happens if the chick can't get out? Should I intervene or should I leave it?
Most chicks hatch by themselves without any human help. It is only those that tend to be in the wrong position in the shell that struggle, or weaker chicks, or where a human has intervened to early and caused more harm than good. So first piece of advise is simply to observe. Chicks can take 24-48 hours to hatch from pipping as they are resting so don't help too early. Be patient.
Another mistake people make is constantly opening the incubator to check on the progress of the chicks. This is detrimental and I guarantee you will do more harm than good. There is also a good chance the chicks can get what's called shrink wrapped. This is where because of the loss of humidity, which comes from opening the lid, the membrane becomes stuck to the chick. At this point without intervention then the chick will certainly die as it will be unable to move freely to allow itself to hatch. TO PREVENT THIS ONLY GO INTO THE INCUBATOR DURING THE LOCKDOWN PERIOD WHENEVER IT'S ABSOLUTELY NECCESSARY. NEVER TAKE THE LID FULLY OFF IF YOU DO. IN AND OUT AS FAST AS YOU CAN.
If you do find a chick shrink wrapped like above, take it out of the incubator and gently and slowly using tweezers try and pull the membrane off. If it's wet it should come off easily. However, if it's dry dab some warm water onto the area you are trying to remove otherwise you'll find that you will pull all the chicks feathers out as the membrane acts like glue. Also the membrane is rich with blood vessels and if the chick hasn't finished absorbing this goodness and you destroy them it will become very weak and there's a good chance it will die. So again don't do this prematurely. Only if you are certain the chick is stuck and will die without your help. If you find blood make sure the chicks beak can get to the fresh air and leave it for a few hours in the incubator. If you successfully manage to get the membrane off and the chick as absorbed the yolk then simply place the chick back in to the incubator.
The main thing to remember when helping chicks is that they only tend to die if there air supply is cut off. So a lot of chicks break through the membrane inside the egg to get to the air sac, but then they can't pip through the actually egg shell to get to the air outside so they run out of air. If you are ever worried about slow progress and want to make sure the chick is alive and you can see some pipping, simply make a tiny hole. This way the chick will be able to breathe and it gives it time to absorb the yolk before you interfere.
Please note many people choose not to interfere at all with the hatching process and that is a totally fine option as well.