Fedora - How to update your system using FEDora UPgrader
The FEDora UPgrader
offers a simple method to update your operating system (as from version Fedora 17 )
Open a terminal as root (administrator):
yum install fedup
Confirm the installation and use of FedUp.
Updating your system
fedup --network 21
by the version of Fedora you want to install.
Learn more: https://fedoraproject.org/wiki/FedUp