[Graphics] Does Anyone Know How To Edit Sprites For Red Rescue Team?

[ChubbyBubby]

You see I'm doing this whole "Rat" Themed series of pokemon streams, and I've already figured out how to make the Starters and Partners Rattata aswell as figuring out of to implement Alolan Rattata into the game (atleast in a gameplay sense). What I need now is to figure out how to edit the sprites of Rattata to match the alolan form, does anyone know how I can do this or what program I need? Thank You in Advance!