# Upgrading from 1.5.3 to 1.5.4

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 these files and directories in your "system" folder with the new versions:

- application/config/mimes.php
- system/codeigniter
- system/database
- system/helpers
- system/libraries
- system/plugins

注解

If you have any custom developed files in these folders please make copies of them first.

## Step 2: Add charset to your config.php

Add the following to application/config/config.php

    /*
    |--------------------------------------------------------------------------
    | Default Character Set
    |--------------------------------------------------------------------------
    |
    | This determines which character set is used by default in various methods
    | that require a character set to be provided.
    |
    */
    $config['charset'] = "UTF-8";

## Step 3: Autoloading language files

If you want to autoload any language files, add this line to application/config/autoload.php

    $autoload['language'] = array();

## Step 4: Update your user guide

Please also replace your local copy of the user guide with the new version.