Source:

https://www.pokecommunity.com/threads/leons-rom-base-shedinja-evolution.434878/

How To

-Change CE762 from 80 00 to C0 00 ( or 00 01 if you expanded to 16 evolution methods, this value worked for me)

-Change CE766 from 44 50 to 00 00

-Change CE858 from 54 44 to 00 00 to make Shedinja's dex entries appear

Happy Hacking!