How to remove "Grand Total to be Charged"

This line is coming from magento. You have to create the local copy of core file and remove it.

1. Make a copy of file

From: app/code/core/Mage/Sales/Block/Order/Totals.php
To: app/code/local/Mage/Sales/Block/Order/Totals.php

after that, remove this part of code

/** * Base grandtotal */
 if ($this->getOrder()->isCurrencyDifferent()) {
     $this->_totals['base_grandtotal'] = new Varien_Object(array(
         'code' => 'base_grandtotal',
         'value' => $this->getOrder()->formatBasePrice($source->getBaseGrandTotal()),
         'label' => $this->__('Grand Total to be Charged'),
         'is_formated' => true,
     ));
 }