Hello! Usually, it can take them quite a while to hatch. If you are very certain that this chick is concreted in and want to help, I can tell you what I have done.
If you have other pipped eggs : take the whole incubator into a steamy hot bathroom and then quickly open and get the egg. Put it on a hot wash cloth and then slowly break away the shell the rest of the way around. Be careful that there is no blood. If blood, then stop and put the egg back in the incubator and wait. If you have to put it back. Moisten a paper towel and drape it over the egg leaving space for the chick to breath. If you can continue, take Q-tips and moisten the membrane on the chick with very warm water. Rub the chick all over to get the sticky membrane off. You should be able to see the chick can now wiggle again. I would then put the chick back in and cover it with a wet paper towel and let it hatch the rest of the way by itself. If it doesn't make it out and gets hard again, repeat the process. Try to work quickly. You may need to use a straw to moisten the paper towel inside the incubator. Make sure you do not drown the chick.
Good luck. Sometimes the chick isn't ready to come out yet, the yolk may not be absorbed all the way. It may have gotten dried out while waiting to absorb the yolk, but if it zipped most of the way around, I would think it was ready to hatch.
