We have a decent wiki page for DNF command-line upgrades
https://fedoraproject.org/wiki/DNF_system_upgrade
but for the GUI we just have a short paragraph here
https://fedoraproject.org/wiki/Upgrading.
It'd be nice to have a graphical walkthrough for people who would
like the comfort of seeing what it will look like in advance. I'd do
it, except I am so excited for F25 that all of my systems are already
upgraded. If no one raises their hand, I'll do it in a VM later
sometime, but in the meantime if anyone hasn't upgraded yet and wants
to help, that'd be awesome.
--
Matthew Miller
<mattdm(a)fedoraproject.org>
Fedora Project Leader