Upgrading from 2.0.2 to 2.0.3
Before performing an update you should take your site offline by replacing the index.php file with a static one.
Step 1: Update your CodeIgniter files
Replace all files and directories in your "system" folder and replace your index.php file. If any modifications were made to your index.php they will need to be made fresh in this new one.
Note: If you have any custom developed files in these folders please make copies of them first.
Step 2: Update CodeIgniter files
Replace the files and directories in your "system" folder with the new versions:
Step 3: Update your main index.php file
If you are running a stock index.php file simply replace your version with the new one.
If your index.php file has internal modifications, please add your modifications to the new file and use it.
Step 4: Replace config/user_agents.php
This config file has been updated to contain more user agent types, please copy it to application/config/user_agents.php.
Step 5: Change references of the EXT constant to ".php"
Note: The EXT Constant has been marked as deprecated, but has not been removed from the application. You are encouraged to make the changes sooner rather than later.
Step 6: Remove APPPATH.'third_party' from autoload.php
Open application/autoload.php, and look for the following:
$autoload['packages'] = array(APPPATH.'third_party');
If you have not chosen to load any additional packages, that line can be changed to:
$autoload['packages'] = array();
Which should provide for nominal performance gains if not autoloading packages.