Here are the steps I've tried so far.
Step 1: Format the 32GB card in camera (No low level available in 5DMK2)
Step 2: Drag Release: v2.3 files over to 32GB CF Card from PC.
Step 3: Update firmware on 5DMK2 from 32GB Card. Successful

Step 4: Copy those files from the 32GB Card to the 128GB card on PC.
Step 5: Replace the ML and autoexec.bin on the 128GB card with the nightly build files.
Step 6: Update firmware from 128GB CF card. Failure.

I can't get past this part.
What am I doing wrong?