You have to update to 10.10 through internet or via alternate CD. You
cannot upgrade from the live cd. With live cd you can only install a
new system. As you said you are not interested in downloading your
installed software again. We suggested to skip it. Because, you should
not use older software
you can easily upgrade from 10.04 to 10.10.
before that need to run update manager to check all the updates are installed
for the current version (10.04).
Then you can upgrade to 10.10 easily and during upgrading it will ask you to
keep the current grub file unchanged or change. in that case you
