How to upgrade Magento?

To upgrade our Magento, we have to follow these steps:

Via content manager

• Log on to Magento backend
• Go to System >>Magento Connect >>Magento Connect Manager
• Fill the credentials

For Magento 1.5 and 1.6 to Magento 1.9.x

• Under “Install New Extensions”, paste connect20.magentocommerce.com/community/Mage_All_Latest
• Then install and proceed

For Magento 1.7, 1.8 and 1.9 to Magento 1.9.x

• Go to Manage Existing Extensions”
• Click on “Check for Updates”
• Click dropdown menu behind the extensions
• Click on Commit changes
• Magento is updated now