Log into your account and follow these steps:
1. Select the menu icon on the top right of the page (to the right of your picture), and under the menu that appears choose Settings, then Account Settings:
2. Under Account Settings, select 'change' next to Email Address to update this information.
3. Type in your new email address, enter your password, and select 'update email'. If your account was created with Facebook, follow the prompts on the Facebook pop up to change your email address.