To update a Nextar GPS device, download from online services the desired updates such as NaviExtras.com, or use the Naviextras Toolbox utility to install them. As of 2015, NaviExtras.com provides certain maps and updates for free, depending on the deals the service has with Nextar.
Download the Naviextras Toolbox utility by navigating to NaviExtras.com, clicking on the Download PC Tool in the Support section and clicking on the Download button. Connect your Nextar GPS device to a computer via the USB cable that came with the device, click on the Log In icon, and type your username and password in the appropriate fields. The utility only supports Windows XP SP3 and newer versions of the Windows operating system
Start the Naviextras Toolbox utility, select the Catalogue option from the navigation panel, and click on the shopping cart icon next to the updates that are compatible with your GPS device. When ready, click on the Checkout button to finalize the transaction. If your GPS device entitles you to free updates and maps, they should be available for installation in the Updates section. Select the Updates option, and click on the Install button next to the purchased or free updates. Before the installation process completes, create a backup of the existing system files on the device by selecting the Backup option when the prompt appears.