To download books, make sure you're logged into HathiTrust.
HathiTrust offers two options for downloading and saving material: downloading a single page or an entire book. While viewing a book, click on Download this page (PDF) or Download whole book (PDF) on the left-hand side of the page.
Downloading a single page prompts the PDF to automatically open in a new tab in your web browser. From there you can save or print the page using the PDF menu.
When downloading an entire book the system may take a moment to generate the PDF. Once it is ready, click on Download PDF. You will be prompted to open or to save the file.