If you have created a style that you no longer need and are not using you would do the following:
- Once signed in as an Administrator or Designed click Themes --> Styles.
- Once the Styles window has opened find the style that you want to delete and select it.
- Once the style has opened click "Delete" to remove the style.
Note: The default styles "Heading 1 through 6 and Normal" are the default ones and can not be deleted.