Use the drag feature in paint (top right icon in the icon section iirc), drag over the item box, hit copy, load up another copy of paint, hit same icon, hit paste, close in the borders around the item, and tada.
Take it into Paint hit select drag around pic move 2 top left then drag bottom right of the white up 2 bottom of your pic and there you go
(this may sound complicated as i just duno how else to put it!)
Copy and paste isn't really that confusing, I just using the key combinations. Photoshop (the one I have at least) automagically creates a new image with the dimensions of the last copied item if it's an image.