The desktop versions for Jaxx Liberty have automatic update enabled so you should not take extra steps to have the latest version. However, if the auto update happens to not work for your device, please visit https://jaxx.io/downloads to download the latest version. Please make sure you write down your 12-word Backup Phrase in the exact sequence prior to updating.
Note: To know what is the latest version of Jaxx, please visit: Using the latest Jaxx Wallet app updates