with my board I had to download the file, put it on a floppy disk.. when you turn on the computer and see the bios.. there should be a key you have to press.. it'll tell you what it is on the screen somewhere.. awdbios or something i don't remember exactly.. press that with the floppy in and it'll do it by itself.
you shouldn't upgrade your bios though unless there is something that you will benefit from from the bios.. if it fucks up you're pretty screwed.