To rename a link, right-click on the link name in the main dialog and select Rename Link. Link names are limited to 25 characters or less due to Excel worksheet name requirements.
If you have renamed a link and want to save it for use in another project, refer to this related topic: Save Link Definition
IMPORTANT: Renaming a link will break the association with existing Excel spreadsheets created using the link. For more information see Excel Naming Conventions.