You can download the file-structure for the CF card with the files belonging to the v2.10 release from within your MyiRex account ('Download attachments').
So, log in your myirex account on
http://myirex.irexnet.com/
Formatting FAT is just well formatting in e.g windows and indicate use FAT when you inserted a CF card and use default clusersize :-)
I have to warn you. If you are uncomfortable with doing this kind of things, better wait for the reflash option for the general public.
I am not a linux expert. But I love to fiddle and play with PCs and devices. So, I have the reflash only as a lifeline in case one of Adam B. programs does an Ooops. :-) Sofar his programs do everything except bricking the Iliad. :-)