That's it! I told you it was easy. If you want to switch back. And if you want to continue cycling through playback devices, press Ctrl + Shift + (A or D) until you get to the playback device you're looking for.
Changing Playback Devices in FxSound
1) Open FxSound
2) Click on the playback devices drop down
3) Click on your desired Playback Device
Changing Playback Device in the System Tray
1) Open the System Tray (up arrow usually at the bottom right of your desktop.