When you need to squeeze more text into a text box or shape without changing the shape’s or font’s size, change the margin between the text and the edge of the text box or shape.
Ctrl+Click the border of the shape or text box you want to adjust the margin for, and then click Format Shape.
On the Shape Options tab, click the Layout & Properties icon and then click Text Box.
In the box for each margin, click the down arrow to decrease the distance. The change is applied immediately, so you can tell when you’ve got it right.