If an Update is ready to be applied to your Google Chrome, just click the three-dot menu in the upper right of your Chrome Web Browser. If you see Update Google Chrome, just click it and it will apply the Update.
If you want to manually check and apply updates, click the three-dot menu in the upper right of your Chrome Web Browser, then on that menu click Help, then About Google Chrome. It will check for any new updates and let you install them.
The browser saves your opened tabs and windows and reopens them automatically when it restarts. If you'd prefer not to restart right away, click Not now. The next time you restart your browser, the update will be applied.