Styles are most easily managed from the Topic Styles pane.
To open the Topic Styles pane, click the dialog launcher in the Style group on the Home tab or on the Format tab.
Select a topic that uses the style you want to modify, and format it with the attributes you want to use.
Do one of the following:
In the Topic Styles pane, click the arrow for the style you want to change.
On the Ribbon's Home tab or the Format tab, click the Topic Style arrow.
Click Update Style to Match Selected topic.
The style will reflect the new formatting attributes, as will topics that use this style .
In the Topic Styles pane, click the arrow for the style you want to delete.
Click Delete.
The topic style will be removed from the Topic Styles pane, and topics that use this style will return to automatic formatting.
In the Topic Styles pane, click the arrow for the style you want to rename.
Click Rename.
Enter the new name for the style and click OK.