Make sure you're signed in to your THQ*ICE Passport account and then click on the following link:
This will add you to our tester pool for the CBT. Invites will be sent out to signed-up Passport holders at random over the course of the test duration. They'll be received as emails to the address listed in your Passport profile and will contain an Activation Key. Instructions on how to apply the key to your Passport will be included (it will be very similar to how keys were handled during the Preview Beta Test). Activation Keys will be sent out to signed-up Passports in regular, measured waves with increasing quantities per wave.