For users that have not yet completed the course, first follow the directions in this article to mark the course complete: http://help.litmos.com/2012/mark-a-course-complete/.
Once the user has completed the course, the completion date can be changed by:
- Navigating to the People
- Select the name of the person to mark complete
- Select the Courses Sub Tab
- Select Edit this result next to the course to change the date for
- Select the calendar icon next to the Completed Date field
- Select the appropriate date
Note: By using the same steps above, the Compliant Until date may be changed
For more on Course settings, check out the "How To: Manage General Course Settings" course in Litmos Dojo.