You can check for updates manually or automatically.
Checking for updates will also look for updates of all installed extensions.
Choose Help - Check for Updates to check manually.
You can disable or enable the automatic check in Tools - Options - Office - Online Update.
on the menu bar will notify you of the update. Click the icon to open a dialogue box with more information.
You will see the Check for Updates dialogue box with some information about the online update of Office.
If you need a proxy server, enter the proxy settings in Tools - Options - Internet - Proxy.
If a newer version is available and Office is not set up for automatic downloading, then you can select any of the following actions:
If Office is configured to download the files automatically, the download starts immediately. A download continues even when you minimise the dialogue box.
If automatic downloads are disabled, start the download manually.
If no update was found, you can close the dialogue box.
You need Administrator rights to update Office.