Step One: Click the "Get Started" button from the invitation email.
Step Two: Click continue to verify your email address.
Step Three: Retrieve the code sent to your email and enter it in the empty boxes.
Step Four: Fill in your first / last name, a user account password, and month / year of birth.
Step Five: A prompt will appear to save the installer to your computer.
If it does not pop up automatically, click on Restart Download. Also, certain browsers might block a popup from appearing.