How to Take Backup and Delete FB Account

How to Take Backup of Your FB Account, 

you may want to download a copy of your information from Facebook:

• Goto Facebook Settings
• Then Goto General Tab
• Click on the link at the bottom of the menu that says “Download a copy of your Facebook data”.
• Note : In this Backup You Also Get Deleted Messages

How to permanently delete your account

If you don't think you'll use Facebook again, you can request to have your account permanently deleted. However, after an account has been deleted it won't be possible to reactivate your account or retrieve anything you've shared on your profile.

Then you need to go to https://www.facebook.com/help/delete_account, click on "Delete my account", then follow the steps to confirm.

It may take up to 90 days for Facebook to delete all of the things you've posted, like your photos, status updates or other data stored in backup systems. While Facebook is deleting this information, it is inaccessible to other people using the social network.