Ah yes, you're doing gods work, too,
@FoxofGrey. I also explained it somewhere else. I hope you're okay if I add my wording for visibility:
In necessary detail, since the guide (https://gist.github.com/khang06/84aabeac507fa99a676d22bb6120cea8#file-0-sd-guide-md) is too god damn vague at the most inconvenient times:
"The hex representation of private", the only line of 16 Bytes in Hex within "private"- aka. "THE CONTENTS OF PRIVATE", for example:
F6 67 A5 9E 8B 62 65 65 AF D5 FF 0D 9E 80 15 8E
THEN open "save\8000000000000043"
from your mounted NAND system partition that you dumped beforehand, right?
The search for "the content of "private" " within "save\8000000000000043":
This means nothing else than to look for the hex digit combination from "private" within "save\8000000000000043".
Make sure that you are
searching for Hex-values in the search (see open tab in "Find"-search mask, HxD editor).
You then copy the next line that come
after your matched search result (=private).
F6 67 A5 9E 8B 62 65 65 AF D5 FF 0D 9E 80 15 8E <= Aforementioned "The hex representation of private", only one line of 16 Bytes in Hex - aka. "THE CONTENTS OF PRIVATE"
A5 6E A5 5E 86 62 35 6D AF D5 F2 0C 9E F0 15 8E <= YOUR SD SEED, the line following "the contents of private"
Lose the spaces and these 16 bytes become your SD Seed: A56EA55E8662356DAFD5F20C9EF0158E