Here is the link http://software.opensuse.org/121/en
you have Internet connection so download the Network upgrade, burn it to CD then reboot your computer with the CD in and follow the steps.
I will suggest that for the upgrading purpose you actually plug your computer to a router instead of doing it wireless.
If your current installation has Gnome desktop manager Gnome 3 is what you are going to get final product. If your computer can't handle Gnome 3 there is a way to roll it back turning the roll back mode.
Also depend on your connection you might need to leave it upgrading overnight
Good luck to you!