I was downloading something from Canvas Commons and accidently imported it to the wrong course. Is there a way that I can go back and remove this imported content without deleting the rest of my course content?
So far as I know you cannot un-import a commons item from a course as a bulk thing. You need to go through item by item and remove whatever that commons item brought in. You can delete individual pages, modules, assignments etc by clicking on the gear next to each item and selecting "delete". You can see what you imported exactly by going to the commons and selecting "imported" at the top.
Is your course unpublished or published? If there was a lot of content and it outnumbers the content you would like to keep, you could start a dummy course, export the data you wish to keep into that, reset your course, and the re-import what you would like to keep How do I copy content from another Canvas course? . I don't think it would be a good idea to do this in a published course if the imported content includes assignments and active grades, but it should be ok so long as there are no grades. I would say the best option would be what I first suggested, going through each item one by one and deleting what you don't want.
Hope this helps,
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