The Edit Original command lets you open most graphics in the application in which you created them so that you can modify it as necessary. Once you save the original file, the document in which you linked it is updated with the new version.
In
the Links panel, select the link and click the Edit Original button . Alternatively,
choose Edit Original from the panel menu.
Select the linked artwork on the page, and choose Edit > Edit Original.
In Illustrator, select the linked artwork on the page, and click the Edit Original button in the Control panel.