If you need to make room for additional buttons, you may want to decrease the size of some of the toolbar boxes, such as the Zoom, Font or Style boxes. Or, perhaps you'd like to increase the size in order to see the entire entry of each option in a dropdown list.
To change the width of a toolbar text button, text box or list box, choose Tools/Customize to display the Customize dialog box and enable toolbar editing.
Next, click on the toolbar box you wish to resize to select it. Then, move your mouse pointer over the right border of the button until the double-headed vertical arrow appears.
Next, simply drag the border to the right to increase the width of the box or to the left to decrease it. After you make the changes, close the Customize dialog box.