HELP! Edit Order Manually - Edit Shipping and Totals

I bought below Extension but don't know how to install it?
The developer seems has left, don't answer question any more.Could someone help me please!

Shall I go to System-Backup/Restore first, back up my files, then select the extension I bought and click " Restore"

Thank you so much for your reply!
Anni

Exension Name Edit Order Manually - Edit Shipping and Totals Rating
License Commercial Votes 2
Price $17.00 Views 9216
Developer davykeenan
Date Added 06/09/10

Here is how:



INSTALLATION & SET-UP
=====================
(1) Unzip and upload just the admin folder to the root directory of your OpenCart installation via ftp.
(2) Backup files as Overwrites list of files below.

Admin (THIS IS FOR THE LINK TO THE EDIT ORDER LIST)
controller\common\header.php
language\english\common\header.php
view\theme\default\template\common\header.tpl

ALL OTHER FILES ARE NEW... DOES NOT OVERWRITE ANY ADMIN>ORDER FILES

Just upload like it say's.

Thanks. But seems like I only can find Language, no Controller and View can be found in the backup ticking box.

My version is 1.4.4, is this a problem? How to install, I only can click Restore or Backup button.

Shall I select the 3 files in Admin one by one , and click restore?