I don't understand it

Why Sambong changed the letter to the viper's one , I don't understand of what help can it be for Bang Won's father D:

WHAT!

I DIDN'T EXPECT IT! I THOUGHT AHJUSSI WAS A GOOD PERSON ! NOW I DONT KNOW IF THE NEW DIRECTOR KNOW ABOUT IT AND HE TRIED TO HELP HIS FATHER , OR HE DIDN'T KNOW ABOUT IT !