Go to ://my.roku.com http://my.roku.com
Create an account. Follow the prompts.
Add in your Credit Card information
After the above - while logged into roku.com Click on the following link:
Once you have added the channel to you account. Start your Roku device and it will automatically add the channel to your device.
If you wish to unsubscribe from the channel.
Go to://my.roku.com http://my.roku.com
Log into your account. You will see manage subscription and just unsubscribe. Note - you continue to have access to your channel until your subscription expiraton.
You may additionally, using your remote control device, on the main channel screen, hit the * button and it will display manage subscription.