This article described you the process to update your version of GLPI in case you are already using it but with a previous version.
Warning n°1 : The update process needs more resources as usual. Please increase your memory_limit and timeout in your php.ini configuration.
Warning n°2 : You need to desactivate all plugins before update GLPI. You also must be sure that all your plugins are compatible.
I) Backup of your old configuration
First of all, please perform the following operations :
Backup your database through the use of backup interface.
Backup the full directory where GLPI is installed (including the SQL database backup and your documents.
From now, if a problem occurs during update or if you do not like the new version, it would be very easy for you to go back to previous version.
However, if you encouter any problem, please warn us on our forum, bugtrack list or mailing list with the used process and the error message you got.
II) Retrieve and install files
Download lastest version tarball available from download section on the website (http://glpi-project)
a) If you update from a GLPI version <0.68 to a GLPI version >=0.68 :
Unpack the new archive and replace the old version by the new one
!- Somes folders have changed since 0.68. If your version is older than 0.68, you must copy their content -!
old_installation_GLPI/backup/dump -> new_installation_GLPI/files/dumps
old_installation_GLPI/docs/ -> new_installation_GLPI/files
Verify or change rights on following folders :
in order that PHP has write rights.
b) If you update from a GLPI version >=0.68 to higher (0.70 for example).
Unpack the new archive and overwrite all files of the old version.
III) Update process start
1) Launch your web browser on this address http://yourserver/your_glpi_path/
2) Select the language into which you want to perform the update process and click on « OK ».
3) Click on « Update».
4) Verify the environment tests succeeded or follow the displayed instructions and try again.
If everything worked fine, click on « next ».
5) Configure MySQL server access while using the config.php file, previously backuped. Fill out : Mysql server : hostname of MySQL server Mysql user : mysql username Mysql pass : password of mysql user
Once this is done, simply click on « next »
6) Select the database you want to update. Then, click on « next »
7) You are asked to confirm you really want to update. Click on « next » if you want to do so.
8) Update begins. It can take a while, depending on the size of your database.
9) Depends on the GLPI version you upgrade, some questions would be asked to you.
10) Process ask you about update the old contents of your database.
After you click on “continue”, a progress bar appears. The process can take a long time, depending on the size of your database and can stay for very long time at 0%.
If you upgrade from 0.4, please read this note 
11) Click on “use GLPI” to perform your connection with the application.
 IMPORTANT : Update from version earlier than 0.4 does not allow you to automatically preserve your detailled configurations (general configuration, external sources, etc) which where stored into config.php file.
You nedd to use the forms from « configuration » menu after the install process.
Those menus are accessible only to a new type of user : « super-admin ».
Update automaticcaly converts « admin » users to « super-admin » users or ask you about creation of a « super-admin » user.
From now, different cases are possible, depending from which version you are updating.
CASE 1 : You add « admin » users or at least one of these users do not use external source to connect.
All your users with « admin » rights and empty password are given « super-admin » rights (you’ll see a notice informing you about this)
Your database is up to date, you now can configure GLPI while clicking on « use GLPI » and using an old « admin » account.
CASE 2 : You do not have « admin » user or all of them have an empty password (all use external source to connect).
Process asks you to create a new user (name and password) with « super-admin » rights. Do not use an existing account !
If this process succeeded, your database is now up to date. Click on « use GLPI » to configure it ! (use the new user you just created)
Once the configuration is completed, you can suppress this user. Be careful that you always have at least one « super-admin » user that can connect to the application from MySQL database, because of eventual external source connection problems.