I take it you are trying to udpate in Windows?
Read further into the SOP at around Page 15 and use the DOS method. First, you will have to make a USB stick bootable. You can't use the forum's USB flasher or it's key for the Ivy update.
This is what the file (example) should look like that you put on the bootable USB stick;
Boot to DOS, type the file name exactly as it is written, press the keyboard Enter key and let it do it's thing. DO NOT RETRACT THE USB STICK EARLY!