Follow the the Sign In button to go to your profile, or visit http://games.crossfit.com/mygames. Registration is $20 for the US, Canada, Europe and Australia and $10 for the rest of the world.
Everyone will need to create a profile and register to compete this year. If you created a profile this year, you will just need to complete payment.
Email support@crossfitgames.com if you have any questions.