Changing pixel inset of GUI texture from scripting

How would I change the pixel inset width and height part of the GUI texture component from scripting? I am trying to make a 50x50 pixel inset width and height texture change to become 100x100.

You just have to assign the pixelInset a new rect:

var newInset : Rect = new Rect(50, 50, 100, 100);
//Rect (x, y, width, height) from the bottom left corner.

guiTexture.pixelInset = newInset;

or in JS, you can edit each value of the rect induvidually.

guiTexture.pixelInset.x = 50;
guiTexture.pixelInset.y = 50;
//and so forth.