<kbd>Fn</kbd>+<kbd>Ctrl</kbd>+<kbd>F8</kbd> will set focus on the "[Status menu][1]" icons on the right side of the menu bar.  ([Section 4][1])

[![enter image description here][2]][2]

Arrows will navigate you to the Keyboard Preferences icon and the Show/Hide options. When you enter <kbd>Fn</kbd>+<kbd>Ctrl</kbd>+<kbd>F8</kbd> the icon to the furthest left side of the "Status menu" icons which are on the right half of the menu bar will get highlighted. Once it is selected, then use the right arrow to navigate to the one you want.  Use the down arrow to open the menu and select the option you want. Note that the <kbd>Option</kbd> key will make different menu options available in some of the "status menus".  

[![enter image description here][3]][3]

Of note, <kbd>Fn</kbd>+<kbd>Ctrl</kbd>+<kbd>F2</kbd> will activate the Apple menu icon  on the left hand side. These options are available in System Preferences >> Keyboard >> Shortcuts::Keyboard:

[![enter image description here][4]][4]

Depending on how you have your Function keys configured, the <kbd>Fn</kbd> is optional.  

[![enter image description here][5]][5]

In macOS Sierra you can also use Siri to help with this. Invoke Siri with whichever keyboard shortcut you choose from System Preferences >> Siri::Keyboard Shortcut, for example <kbd>Option</kbd>+<kbd>Spacebar</kbd>  

[![enter image description here][6]][6]

...then say "Turn on the Keyboard Viewer"  

[![enter image description here][7]][7]

...and voila:  

[![enter image description here][8]][8]

Unfortunately, Siri will not close the Keyboard Viewer, nor will <kbd>Command⌘</kbd>+<kbd>w</kbd>


  [1]: https://support.apple.com/en-us/HT201956
  [2]: https://i.sstatic.net/JVbnX.png
  [3]: https://i.sstatic.net/qgnjl.png
  [4]: https://i.sstatic.net/ikQ3d.png
  [5]: https://i.sstatic.net/BAlFk.png
  [6]: https://i.sstatic.net/PeJCX.png
  [7]: https://i.sstatic.net/8QZDA.png
  [8]: https://i.sstatic.net/bJGWX.png