If your wish is to temporarily deactivate your Facebook account, please check the following post:
Before you completely delete your Facebook account, you are advised to do the following:
Now if you are ready to completely delete your Facebook account, login to the account which you would like to delete and then click the following button which will take you to the official Facebook help page for deleting your account, where you will be asked to confirm that you want to delete your account and complete some security questions such as confirming your password.
Now that you know how to delete your Facebook account, share this post with your friends to let them know how they can delete or deactivate their account on Facebook.