I imported a course from commons and want to delete it. How do I detach it from my courses?
You can't really "detach" it, because the content has actually been imported into the courses, just as if you had imported from another. The only real option is to manually delete the imported content in each course.
If you didn't have other content in the courses that you wanted to save, you may be able to do a "Course Reset" ( How do I reset course content? ), which basically nukes all the content in the course, providing your school has set Canvas to allow instructors to do a reset.
Manual cleanup can be a pain, depending on how much was imported. We always advise instructors to import materials from Commons into a sandbox/test course first, to make sure that it's what they are expecting before importing into "live" courses...
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