I would leave it along. Just make sure this one has a safe space to not get tackled by the other while he absorbs it...
Maybe you can make a barrier in one area to keep him from moving around too much for a few hours and see how it goes?
Have you had this happen with good results? I'm worried about infection because
it dragged around the bottom of the incubator with all the mess from the other
eggs hatching. Would it kill him to snip and cauterize? Wahh!
As long as none of the other chicks are pecking at it, there shouldn't be a problem. It will most likely absorb and dry up in a day or so. If the others ARE pecking at it, separate the chick until the sac has absorbed. But it really should dry up on its own quite quickly. I think snipping it off would be a really bad idea...
Poor baby! I had a duckling hatch with his yolk sac not fully absorbed. I wrapped him, aside from his head, in a warm, damp towel and kept him in the incubator for a few days and he did just fine. You might try that out, it'll keep the chick damp enough and not allow the other chicks to peck at the yolk sac. Just be sure to change the towel every now and then so bacteria don't grow. Best of luck, I hope your little one makes it!