To download an Audit Trail, simply open the Audit Trail pop-up window (for more information on how to access your Audit Trails, please see: How do I view the Audit Trails for my Team? or How do I view the Audit Trails for a Binder, Folder, or Document?).
In the Audit Trail pop-up window, you'll notice a link to download the Audit Trail as a CSV or PDF. Simply click on either of these links to download the Audit Trail as a document.