I can't tell you exactly what to do. But I'd but into lockdown with moisture. Or I'd carefully wet the membrane and if I see no veins tear a hole near the beak. But I have helped hatch before. Without being able to see more it is hard to advise. I'm surprised it isn't internally pipped it may not actually be ready to come out and need more time. I'm afraid at day 24 I'd have to think about helping but there are people who have reported hatching at day 25 so you could put it in a moist lockdown situation and wait.
Type assist hatch or assisted hatch in search and do a little reading. THere are lots of choices and of course at this point the chick may not live no matter what you do it isn't always a matter of doing it right.
Type assist hatch or assisted hatch in search and do a little reading. THere are lots of choices and of course at this point the chick may not live no matter what you do it isn't always a matter of doing it right.