# CodeIgniter User Guide Version 2.2.3

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# Upgrading from 2.0.1 to 2.0.2

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: Remove loading calls for the Security Library

Security has been moved to the core and is now always loaded automatically. Make sure you remove any loading calls as they will result in PHP errors.

## Step 3: Move MY_Security

If you are overriding or extending the Security library, you will need to move it to `application/core`.

`csrf_token_name` and `csrf_hash` have changed to protected class properties. Please use `security->get_csrf_hash()` and `security->get_csrf_token_name()` to access those values.