To open the formatting dialog box for a chart element, double-click that chart element. When selecting elements, you can press the keys to move the selection handles from one major chart element to another, or the keys to toggle through chart sub-elements.
Text box
To add a text box:click the Drawing icon to display the Drawing toolbar, then click the Text Box icon . Click and drag to draw a rectangular area where the text will go, then release the mouse button and type your text. Press ESC when done.
To change the text box size: click and drag the text box handles.
To move text: drag the text box border, not the box's handles.