ROM Hack Changing button configuration?(Final Fantasy IV)

[Japhle]

Basically, I can't use my R button, Which means that I cannot escape from battles, which would be something I would like to be able to do.
So in simpler than basic words, I need to switch either my Left shoulder button or the select button with my Right shoulder button.


So any help or info about that type of thing would be helpful, If you would...

Edit:also I'm using an M3 real with the triple loader firmware. Not that it matters much.