You can easily upgrade your distribution using fedup:
First of all install the fedup package:
yum install fedup -y
Before starting the distribution upgrade you should be sure to have your system up-2-date:
If there are kernel updates etc. in the above update, you should reboot your machine before continuing.
Then start the upgrade:
fedup-cli --reboot --network 20
Whereas 20 corresponds to the currently most recent version – codename Heisenbug – you should change it accordlingly.
For a list of available distributions, have a look here!
The reboot option is optional, but will restart your machine once the update is completed!