You can un-publish your course at any point of time. To un-publish a published course -
- Go to Courses in admin dashboard. Select the published course which you would like to un-publish
- Click on Unpublish button in the course builder page. Click on confirmation popup to unpublish
- In settings page click on un-publish button
Note: If there are students enrolled you cannot un-publish course. You first have to disable all the students enrolled to that course and then click on unpublish again.