When you delete styles, the appearance of paragraphs tagged with the style doesn’t change, but their formatting is no longer associated with a style.
Choose Delete Character Style or Delete Paragraph Style from the panel menu.
Click the Delete icon
at
the bottom of the panel.
Drag the style to the Delete icon at the bottom of the panel.
To delete all unused styles,
choose Select All Unused from the panel menu, and then click the
Delete icon.