# CodeIgniter User Guide Version 2.1.2

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# Upgrading from 1.6.1 to 1.6.2

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

- system/codeigniter
- system/database
- system/helpers
- system/language
- system/libraries

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

## Step 2: Encryption Key

If you are using sessions, open up application/config/config.php and verify you've set an encryption key.

## Step 3: Constants File

Copy /application/config/constants.php to your installation, and modify if necessary.

## Step 4: Mimes File

Replace /application/config/mimes.php with the dowloaded version. If you've added custom mime types, you'll need to re-add them.

## Step 5: Update your user guide

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