Deleting a style removes it from the Styles palette. Any objects, groups, or layers that used the style retain the same appearance attributes; however, these attributes are no longer associated with a style.
To delete a style:
In the Styles palette, select a style you want to delete.
Delete the style:
Choose Delete Style from the Styles palette menu.
Click the Trash button in the palette.
Drag the style onto the Trash button in the palette.