Click on the "edit" link to see the following screen. From here, you can make various changes to the course, its grade level, assigned sections and course credit information, among other things. Select "No" under "Active" to deactivate a course, and click the green save button to finalize your change.
Schoolrunner doesn’t truly delete anything (including courses), but it’s possible to deactivate items like this. Note that if the course you are deleting is based off an active course in your SIS, it may become reactivated the next time Schoolrunner syncs with your SIS. Contact your Schoolrunner administrator for more assistance.