I have an old T61 notebook with Fedora 23. Since this distribution release is quite outdated I upgraded to the latest release version (27) this weekend. This can be done quite easily with the dnf-plugin-system-upgrade package.
$ sudo dnf install dnf-plugin-system-upgrade
$ sudo dnf system-upgrade download –refresh –releasever=27
$ sudo dnf system-upgrade reboot
If all goes well Fedora will upgrade to release 27 after the next reboot. I had to uninstall a few packages first, for which dnf complained about dependency conflicts.
For more details check out the Fedora Wiki.