1.) Log into CloudFlare: https://www.cloudflare.com/a/login

2.) Select the website you wish to delete from your list of websites.

3.) In the Overview app under Status, click the Advanced link to display the advanced settings.

4.) Click Delete.

5.) Click Delete to proceed with deleting the domain.

6.) Repeat steps 4-7 for each website.

7.) Click your username in the top of the page and then click My Settings.

8.) Click Billing.

9.) Click the Delete link to remove your credit card information.

10.) Create a support ticket asking for your account to be deleted. Once deleted, the email used cannot be used again at CloudFlare.