Im sure you'll get both sides here in about 10 min. One side will say Absolutely NO!! that you're helping weaker chicks survive that maybe shouldn't and that these weaker chicks my make your stock weaker in future generations.
Then you have another side... the side I lean toward if you aren't breeding toward the standard of perfection or showing or aren't planning on selling your birds. This gives you the ability to decide whichever way you want to go
without concern. If you decide to help, here is a couple tips.
If a chick has been in the shell for that long with a pip, the membranes are starting to dry up and its ready. Begin by breaking a larger hole and work around the side just like it would naturally hatching. Work a bit then stop and let the eggie rest for an hour or two... then go at it again. The whole thing may take 6 hours or so but this gives all those veins and chance to dry. If you see blood (you will) just stop and let rest then hit it again in a couple hours. Once the baby has "hatched" have a paper towel moistened (with warm water) ready and lay it on that so its navel doesn't stick to the wire. It probably won't be able to walk til tomorrow.
If they haven't pipped yet, candle and see if the beak has pipped the air cell. You should see a shadow if it has. I would make a pip hole and see what's going on in there. Then, same thing. let it rest. You can tap on the eggs and chook chook at it and hear the peep calling back. This will let you know if it's still alive. GOOD LUCK!!
ETA: I just read Tuffoldhen's post and she's probably right. Just keep an eye.. as long as it has pipped, it has air. And, most people don't start busting in there til day 23.
