Choose View - Styles or press F11
.
Click the icon of the style category that you want to update.
In the document, click from where you want to copy the updated style. For example, click a paragraph to which you applied some manual formatting that you want to copy now.
In the Styles window, click the style that you want to update.
Click the arrow next to the Style actions icon and choose Update Selected Style from the submenu.
Only the manually formatted attributes of the text at the cursor position in the document will be added to the style that is selected in the Styles window. Any attributes that were applied as part of a style will not be added to the updated style.