help with spritesheets reassignment

[owlknight]

okay need help with something here

http://www.ffhacktics.com/forum/viewtopic.php?t=1828

I have read this and have no idea how to use this info.
I can patch them no prob
but its what i can after that also don't know what this "dummy" folder is.
where it is, how to view it, or what program to use.
any help would be most appreciated