yeah, hot flash is possible, did it a few times with the older, bigger chips with those fiddly legs older mainboards did have (if you remember..).. i think that was even more risky

just loosen the chip that it will be easily removed whilst the board is working, boot, take away the bioschip and place a new one in, flash...

But I'll think of getting some preflashed from DFI or ebay as a spare...