Answer:
1. Select text in your document that has the style applied, such as Heading 1.
When you select the text that has a style applied, that style is highlighted in the Styles gallery.
2. Format the selected text with the new attributes that you want.
For example, you might want to change the point size for the Heading 1 style from 16 points to 14 points.
3. On the Home tab, in the Styles group, right-click the style that you want to change and then click Update [Style Name] to Match Selection.
Explanation: Hope this helps you!