To modify the lightbox text:
1) Navigate to /admin?action=list&path=/xml_content/phrasepacks/v3, click on the Layer7 icon to the right of the dashboard-display.xml file -> Edit PhrasePack -> Standalone
2) Search for Close Message in the list to find the line and change the value:
3) Click Save at the top of the page
4) Click the L7 icon -> Publish
Sincerely,
Stephen Hughes
Director, CA Support