Mike these are the exact instructions shared with me by a major breeder. I did this last year and every one of the snakes came out beautifully with no excessive bleeding from the cut egg and with fully absorbed yolks.

Take the eggs in the egg box into a dark area, candle them and put a light pencil line on an area where you see no major veins and the snake is out of the way.

Return to a well lit area, find your pencil line, pinch it slightly to raise it up. Cut carefully using small curved cuticle scissors creating a V. Enlarge as needed then cut off the bottom of the V creating a nice neat triangular opening. Very gently squeeze the egg to express a small amount of the liquid out of the egg. Gently wipe away any egg goop that comes out with a paper towel.

Replace the egg in the egg box in it's original position.

Once the eggs are cut and until all the snakes are fully out of their eggs, open the egg box and gently mist the eggs once or twice daily. I kept a small mister bottle right in the incubator so the temps of that water matched the incubator temps.

Hope this helped.

P.S. I was literally shaking and terrified the first time I cut into an egg. It does get way easier with practise.