Follow the directions to make a Moodle account, or login if you already have one.
After logging in you should see this page.
Scroll on the page and click on the course you want to enroll in..
Scroll down to the bottom of the course page and click on the button Enrol Me.
You should now see this page, and are free to begin the course. Please remember that you have 3 weeks to complete the course before your enrollment expires.