Hi! Sort of duck person here. Just to be quick and concise, if its been a long, long time, and few to no blood vessels are present in membrane directly under when you dampen it to render it translucent, peel back the shell slowly, gently, piece by piece until half way, then keep him moist for a few more hours and give him a chance to struggle out of that. A little water or even sugar water on the beak for a drink might help too. If he doesn't, check to make SURE his yolk is absorbed and help him out, keep him warm, get him sugar water or just plain water, but do not give him enough to drown in while he is weak. After that, you just have to wait to see if he has what it takes to live. He may, he may not.