Well, I finally got it. I just needed some sleep and some food. I copied all required files to the USB stick but for the life of me I couldn't get it to boot into EFI. After a little looking around I could this:
Note: If you are unable to launch UEFI Shell from the firmware directly using any of the above mentioned methods, create a FAT32 USB pen drive with Shell.efi copied as (USB)/efi/boot/bootx64.efi. This USB should come up in the firmware boot menu. Launching this option will launch the UEFI Shell for you.
That worked perfectly. I was able to boot into the shell and upgrade the firmware. Thanks for the help.