If you have an extension installed, but you want to upgrade to the latest version, then you can follow these steps. You must be logged in to the TYPO3 backend with administrative access.
1. Click on the Ext Manager module in the left column.
2. Choose "Check for TER2 updates" on the dropdown menu.
3. At the bottom of this page, click on "Get version info from online repository". This updates this list to the latest extensions. This may take a minute or so if the servers are slow.
4. Find the module you want to update and click on the Module name.
5. Now select the "to: Local..." if it is not already selected. Then you can click on "Import/Update" button.
6. Click on "Make Updates" if there are any updates. Your new extension should be installed!