How to Delete Your Facebook Account, Permanently
Before deleting your Facebook account, you might want to download a copy of your personal data that was stored on the Site. You can find Facebooks instructions to download your Facebook data here if interested. If you don’t download your personal data, then it will not be available to you after you have deleted the account.
- Open any web browser and go to the Facebook “delete account” page found here
- Click on the “Delete Account” button
Source: How to Delete a Facebook Account