If none of the above tricks work with your BIOS (meaning it is able to boot only from first CD/DVD drive it finds), I'm affraid rewiring is (almost) the only option. Almost, because there's one more trick you can try. If you don't want to rewire, you might try downloading Rescue CD (80MB or so ISO image) and burning it to CD.
No need to download that; the rescuecd.iso image is in the images/ directory of the DVD.
Paul.
