I can't upgrade through do-release-upgrade due to a slow internet connection, so I downloaded the iso file, and mounted it:
sudo mount -o ro ~/kubuntu-14.04-desktop-amd64.iso /media/emcdrom
It's mounted, ok, But there is no any autorun or *.sh's, so what I should do next?
p.s. i know, in old (10., 11.) distributives it will be done by kdesudo "sh /media/cdrom/cdromupgrade" command, but, like i already said - there is no cdromupgrade.sh or any other *.sh. Only wubi.exe and grub boot core.