1. Connect Manager
Log on to your Magento Dashboard and navigate to System >> Magento Connect >> Magento Connect Manager then fill in your credentials:
If this is the first time you log in to Magento Connect (i.e. no packages are listed under the ‘connect.magentocommerce.com/core’ channel), you will need to prepare the downloader by typing “connect20.magentocommerce.com/community/Mage_All_Latest” in the Extension Key field, and then click on the Install button:
Once the initial setup procedure has completed, click on Proceed.
Check the output frame if the procedure completed successfully:
Upgrading Magento 1.7, 1.8 and 1.9 to Magento 1.9.x
Upgrading Magento 1.7 or 1.8 to version 1.9 works slightly different than upgrading from an older version.
Go to “Manage Existing Extensions” and click “Check for Upgrades”.
Extensions that can be upgraded will have a yellow background color.
Click on the drop-down menu behind the extensions that can be upgraded and choose the newest Magento version.
Once you’ve selected everything scroll down and click on “Commit changes”.
Your Magento is now upgraded.
If one of your extensions or plugins isn’t compatible with the next Magento version, then you can’t upgrade Magento via the Connect Manager and you’ll need to use:
Login to Softaculous and open All Installations:
If your Magento is not in Softaculous, then you can import it.
If an upgrade is available, you’ll see an icon next to the current version. Hover over the upgrade icon to get the version to which you can upgrade:
To upgrade, click on the icon, then select create a backup (recommended) and hit Upgrade:
Allow about a minute for Softaculous to upgrade Magento:
You can also enable Auto Upgrade by editing the application in the Softaculous >> All Installations screen:
Connect to the server via SSH and enter the Magento installation dir.
chmod 750 mage
./mage mage-setup .
./mage config-set preferred_state stable
./mage install https://connect20.magentocommerce.com/community Mage_All_Latest --force
php shell/indexer.php reindexall
rm -rf downloader/.cache/ var/cache/
php -r 'require "app/Mage.php"; Mage::app()->getCacheInstance()->flush();'
Congratulations, you have now successfully upgraded your Magento store to the newest version!