[Graphic✓] Is it Possible to change the item sprites that already existed in the Rom?

As you can see the thread title: Is it Possible to change the item sprites that already existed in the Rom?
Hope someone could help me :D

Yes, it's very possible and doable... Just use your favorite sprite importing tool to import the sprite and the palette to a free space and repoint the sprite and palette used by an item using your favorite item modification tool...