Everything I search is based on the old UI.
I've tried the following
button.image = Resource.Load<Image>("...");
button.GetComponent<Image>() = Resources.Load<Image>("....");
button.GetComponent<Button>().image = Resources.Load<Image>("....");
button.GetComponent<Image>().sprite = Resources.Load<Sprite>("....");
I want to change the button image on an event.
Tested and Working.
Also you can use the properties of Button Component
http://docs.unity3d.com/Manual/script-Button.html
Specifically you can set the button's behavior based on events.
Example:
And then :