First double-click on the text box that you want to edit. Then click on the 'Font' tab in the 'Editor' to see the formatting options. Next select the piece of text you want to change, and then type a new number into the 'PT' field (shorthand for 'point' size) on the 'Editor' and press enter on your keyboard (don't worry if your text deselects, SiteMaker remembers what was selected). The selected text will change size. Remember to save your changes.