Oh here's how I helped one out of its shell when I had a humidity issue and the exposed membrane had changed color indicating it had dried -
Hot water on a paper towel or two, by the time you get to the egg it will be cooler, wet but not dripping, take out the egg quickly, wrap it mostly in the warm and damp paper towel and gently dab the exposed membrane for a few minutes.
Pick off a zip line of shell from where the chick pipped (I looked this up online) being very careful not to damage the membrane and put it back in the incubator still mostly wrapped up (but not very tight, more like a sideways cup, you want it to hatch itself) with the initial dried up exposed membrane side facing out of the paper towel, keeping in mind this will bump up your overall incubator humidity until the towel dries out...
If all goes well, the chick will be strong enough to safely proceed as normal with a wet membrane and a bit of help with the zipping. I only had to do it once and it worked and the chick survived fine so I don't have much experience but it could help in the future!