Go to the FILE section and indicate that you want to 'mail your return' on the page asking you to choose Mail or Efile.
Then click on the link to 'Preview your Return'. A separate window opens and populates with a PDF file of your return.
Save this file to your computer, and Continue through the rest of the FILE section, where TurboTax asks how you want your refund or how you want to pay your balance due.
You can then print your return from the PDF file you've saved on your computer.