One of the techniques I use for particularly difficult hatches after oiling the membrane and loosening the head away from the 'tucked into the wing' position, is to again gently wiggle the head loose (if needed) and then while holding the egg in one hand and my other hand underneath the egg, slowly turn the egg upside down where the chick's head is dangling from the opening in the shell, allowing gravity to do most of the work with very very gentle encouraging pulls but no tugging, the baby is still attached to the shell and may not have fully absorbed everything it needs from it. If you managed to get the chick in hand, place it and the attached shell back into the incubator for an hour or two. You'll then be looking for the umbilical cord to dry out enough to cut it in the narrowest spot with scissors at the closest spot to the shell, or with excellent luck, the chick to have finally kicked the shell off of itself. If the umbilical cord doesn't look dried up enough after a couple hours, keep checking back hourly. You can expect the chick to chirp (complain) long and loud while in the incubator after it's no longer trapped in the shell, I guess that's to be expected as it's had one very difficult entry into the world. It's not uncommon for the chick to fall asleep after it's no longer stuck in the shell too. Quail chicks sleep soundly, I'm often tempted to open the incubator to check to see if they're still alive. Hang in there, you're doing a great job!