Log into TurboTax with the account you used to purchase TurboTax Deluxe. This opens the My TurboTax page for your product. Near the top of the page, click My Downloads. This opens a list of all the products you have purchased for download going back several years. Your 2016 product should be at the top of this Downloads list. Click Download for the 2016 product you purchased and follow the instructions to download, run the installer, and start TurboTax.