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This is great advice. I would add that candling can also help you see when the membrane is clearing, and it is beneficial to time the process, noting when chicks pip internally and when they pip externally if you can. That can help you from intervening too soon, or too late. Either can be fatal. Take advantage of every opportunity to practice candling so you become familiar with what various things look like and how to identify what you are looking for.
Also, I would be EXTREMELY cautious about breaking any shell. That can allow a chick to get out too soon, before the blood has gone completely into the chick or before the chick's navel has closed, resulting in chick death. Bear in mind that peachicks are very strong -- even when weakened a bit by the hatching struggle, their legs are still extremely strong. Removing any shell at all can sometimes allow a chick to burst out before the chick's body is physiologically ready to do so. Monitoring elapsed time and having a very solid understanding of the hatching process can help save chicks from well-intentioned errors.
Also, the more shell that is broken, the more drying occurs in the membrane, which virtually guarantees a shrink-wrapped chick which will ultimately need to be rescued. Some people use wet paper towels to try to keep the membrane from prematurely drying out. Note that there are two different things happening to the membrane. First, the blood circulating through it (like the placenta in a mammal) is carrying oxygen to the baby chick before the bird starts breathing air. That blood needs to go inside the chick's body, which incidentally makes the membrane less opaque when candling, and results in the many blood vessels in the membrane gradually shrinking up as the blood leaves and is not replaced. Until that happens, the chick may bleed to death if the membrane is disturbed. The other thing that happens is that as the membrane itself is exposed by the chick's fracturing of the shell (or the human breaking the shell), the moisture in the membrane evaporates and the membrane dries out, shrinks and becomes brittle. Those aren't the same thing, so another place to observe carefully and learn the difference in your eggs/chicks. Sometimes folks will put a drop or two of water on a white membrane (which makes it more transparent) to see whether the veins have shrunk.
Even after the veins have shrunk, the navel has closed and the chick is ready to hatch, there will be a tracery remaining in the membrane (visible on the inside of a hatched chick's shell) of the veins that carry blood through the membrane -- they don't complete go away, and there will usually still be a faint pinkish or reddish blood tinge -- again, learning what that looks like can make the difference between successfully hatching chicks and failure.
As @barkerg has mentioned, this is a process that takes experience, and there is a lot to learn hands-on. I cannot emphasize enough how important it is to read up -- many good threads here on BYC, including on the chicken side of the house. Happy Easter!