1. Select and export ads into a sheet
2. Clear values in the Campaign ID, Ad set ID and Ad ID columns.
3. Select import ads in bulk and upload your sheet.
Note: If you’re getting an error for ads with multiple headlines can’t be exported or an empty sheet. You need to delete manual & automated “Advantage+ creative text generation” options.
4. All done
Note: Remember to change accounts otherwise you’ll get a pixel error.
Original Meta guide :https://www.facebook.com/business/help/1419087678312537