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How to set your a/v file as the primary bitstream
When you deposit a new item to the repository, you have the option to designate any file as the primary bitstream during the submission workflow.
If you need to set the primary bitstream after an item is already published, take the following steps:
Navigate to the item in question and click "Edit this item" in the right sidebar.
Click the "Item Bitstreams" tab.
Click on the bitstream you want to make the primary. You'll want to click on the linked title of the file. This should take you to the "Edit bitstream" page with the file metadata.
Under "Primary bitstream," click on the dropdown menu and select "yes."
Click Save.