Once you have purchased the manual under your account, you can go to your Account Portal to download it (or you can view the email sent to you). Remember that you will need to register the account first then login and purchase the manual while in that account; otherwise you will end up putting the manual into a separate unregistered account. This is the same process when done on the computer.
Email download link
You can also access download link via your email receipt once your order has been marked completed (which is immediately after payment). See the screenshot below of which link to click to download: