You need a floppy bootdisk and boot with it. After you prepare the files..
Make a partition on your HD 2 gig or so and IMPORTANT format FAT32.
download the floppy versions of firmware. run them to unzip. For ease of use, collect the binaries and dos folder contents and put them in the root of the new FAT32 partition in folders with short names that work for you.
I used the most current files as of 4/2013
For the BMC - BACKUP - socflash -t 1 BMCBACK.ROM
then flash socflash -sf romfile.rom
for Bios afudos romfile.rom -x -reboot
for fan fcbflash -o file.bin
Use whichever names the rom files are named.
I had a few mishaps before I got this to work, NTFS Bootdisk does not work. Thought I lost my BMC. using the above method resurrected it.
SIDE NOTE: I did run the windows BIOS update after I booted up, and reinstalled. But I was just paranoid. But you can use the current update files in Windows after you update to a more current version.