You can remove existing embedded styles that are part of a topic. When you remove an embedded style from a topic, the formatting applied by the style is removed. You can also remove any custom formatting for any of the default styles such as Normal and Heading 1, although you cannot remove the default style itself.
On the Format menu, select Styles. The Styles dialog opens.
Under List, select All Styles.
Under Available in, select the topic name (not the style sheet name). This allows you to remove embedded styles for this specific topic.
From the Styles list, select the style you want to remove.
Click Delete. The style is removed from the file.