By Bios model, do you mean the, "Xecuter Rox My Box," logo or the flubber?
If you mean the XRMB logo, then you begin by opening MS paint and resizing your window to 180x50. Make the logo as you wish (mine says, "Microsoft" with bullet holes going through it, and another caption, "Killed by X3."). When you get finished, then save it as x3logo.bmp IN 256 COLOR BITMAP. If you don't do this it won't work. Then FTP the box and save it in the root of the E drive. Restart XBox. You should have a fancy logo now. There, wasn't that easy?
If you mean the flubber... sorry, I'm clueless. I have no idea. I've been working on that one for awhile now. I dunno.
- Greg