Here's the procedure (for me at least):
When you sign up for the newsletter you will receive an email with a link to confirm your subscription (it may take a while to come through)
Click on this link. Don't worry about the page that opens up.
You will then receive a second email with a link to download the magazine.
You can then do the "enter the xxx word in the large headline on page xxx" business in order to access the downloadable software.