1. Boot up Retropie and exit out of Emulation Station using the GUI. This will get you to the shell/command line. From here do the following:
Type sudo nano /boot/config.txt (this will open the config.txt file in an editable form)
2.Find the following line and remove the "#" to uncomment out the setting (make them live)
3. Add the following (anywhere in the file; I did mine at the top)
4. Save by holding down the CTRL-X keys and type "Y" when is asks you to save and overwrite the current file
5. Reboot Retropie by typing in sudo reboot
BOOM! All should be fixed. Open a game and confirm all is well!