Adobe Illustrator CC 2015 - Manual (Page 459)

454
Creating special effects
Last updated 6/5/2015
The replaced graphic style keeps its name but takes on new appearance attributes. All occurrences of the graphic
style in the Illustrator document are updated to use the new attributes.
Import all graphic styles from another document
1 Choose Window > Graphic Style Libraries > Other Library or select Open Graphic Style Library > Other Library
from the Graphic Styles panel menu.
2 Select the file from which you want to import graphic styles, and click Open.
The graphic styles appear in a graphic style library panel (not the Graphic Styles panel).