Put the RC2 DVD in your drive with RC1 running, the installation will start
up and default to an upgrade of RC1 (if you have enough free space on the
partition) and offer you an option for a custom install if you want to
install RC2 elsewhere.
At anyrate, unless you know someone with the file, you won't be able to get
it. It's was only available for a limited time through the Microsoft site.
Try googling for it and be patient and you'll find it. I did