You need to edit the byte near the beginning of a character block. Typically, a character block begins with
Code:
07 xx xx xx xx xx xx xx xx ...
If you want anyone can use Fujin Yumi, just edit one byte to 0x40:
Code:
07 xx xx xx 40 xx xx xx xx ...
Similarly, you can also edit some bytes to allow other characters to use exclusive weapons:
Yato:
Code:
07 04 xx xx xx xx xx xx xx ...
Raijinto:
Code:
07 xx xx xx 80 xx xx xx xx ...
Brynhildr:
Code:
07 xx xx xx xx 01 xx xx xx ...
Siegfried:
Code:
07 xx xx xx xx 02 xx xx xx ...