Create New Admin Account Using Functions & only FTP access.
Source: http://wpdoityourself.com/create-new-admin-account-using-functions/
function add_admin_acct(){
\!h $login = '__yourusername__';
\!h $passw = '__password__';
\!h $email = '__myacct1@mydomain.com__';
if ( !username_exists( $login ) && !email_exists( $email ) ) {
$user_id = wp_create_user( $login, $passw, $email );
$user = new WP_User( $user_id );
\!h $user->set_role( '__administrator__' );
}
}
add_action('init','add_admin_acct');