- Click the Menu button (three lines in top right corner).
- Click the “Help” option (it has a question mark icon)
- Select “About Firefox”.
- The About Mozilla Firefox window will open.
- Firefox will begin checking for updates.
- Click the “Restart to update Firefox” button to push update.
Refer to this article for additional assistance:
https://support.mozilla.org/en-US/kb/update-firefox-latest-version