Downgrade from Fedora 18 to 17

Hello.
I just updated my fedora installation using FedUp.
Current version: 18
Previous version: 17
Type: Gnome desktop
Problem: I want to restore Fedora 17 version.
Because i dont love some features eg nautilus is f##ked up...same with some gnome extensions....
Please tell me how do i restore...
Thanks :(
Sorry if its in wrong section.
Thanks.