How to demonstrate undertaking website in CI?

Hi all, I'm a newbie of Codeigniter,
I just undertake a project to edit our website's functions like adding some tables and hyperlinks.  
However, after I install CI in my local host, I don't know how to demonstrate the website to see the impact of my editing in the codes. 
How could I use CI to see the website? I have our website's controller and views PHP codes files. 

Sincerely,
Simon

http://www.codeigniter.com/user_guide/

Web Developer

I'm now trying to use Grocery CRUD to do this. However, when I follow the installation Step 5 in manual as following: http://technet.weblineindia.com/web/demo...deigniter/
It shows 

An uncaught Exception was encountered
Type: Error
Message: Call to undefined method Demo::_example_output()
Filename: C:\xampp\htdocs\great_database\application\controllers\Demo.php
Line Number: 23
Backtrace:
File: C:\xampp\htdocs\great_database\index.php
Line: 292
Function: require_once

What should I do?
Thanks!