Instructions
Navigate to the Battle.net website.
Click "Log In" at the top of the page. Log in using the email address and password you use to log in to "World of Warcraft."
Click "Account" at the top of the page.
Click your "World of Warcraft" account. If you have multiple accounts, click the subscription you want to cancel.
Click "Cancel Game Subscription." Select your reason for canceling from the menu that appears and click "Yes, Please Cancel My 'World of Warcraft' Subscription." Your subscription will be canceled at the end of the current billing cycle.