In the library, make your listing selections and click the Bulk Actions button.
The Bulk Actions button will appear towards the top right of your screen once at least one listing is selected.
Choose Edit Listings, then Buyer Requirements.
In the popup, select to Edit this page of listings only or Edit all listings at once and select Next.
If you selected to edit this page of listings only, on the next page you're able to set the buyer requirements for all of the selected listings at once or set the buyer requirements individually per selected listing.
Then click Save all modified.
If you've chosen to Edit all listings at once, set your values in the popup and choose Edit Listings.