Just like the guide says, this is the most successful path to upgrading modern Fedora versions:
sudo yum update fedup fedora-release sudo fedup --network 20
This upgrades from Fedora 19 to 20. Adding the
--reboot option to
fedup will automatically restart the system. You should then see a System Upgrade entry in grub’s menu. Selecting it should continue the installation process, replacing your previous packages with the upgraded ones. I can personally vouch for a smooth experience.
I dual boot Fedora and Windows 7, and apparently Grub 2 has been having issues on Fedora that prevent you from editing the boot menu, so previous kernels stay listed. Has anyone else dual booting with Fedora found a way to deal with this?