Upgrading Fedora from Version Spherical Cow version 18 to the latest Schrödinger’s Cat version 19.
The official Fedora documentation is a good friend.
All following steps as root or with sudo;)
1. Backup your system
2. Do the upgrade
yum install fedora-upgrade fedora-upgrade
You will be asked at the end for a reboot
After reboot update yum to latest version available in your Fedora version
yum update yum
3. Clean up
yum clean all
Enjoy Schrodinger’s Cat