Note that these are bleeding edge packages and may contain bugs so beware of 'rough' edges.
To install KDE SC 4.10 RC1 in openSUSE, add the KDE:Distro:Factory repo in your software sources (replace 12.1 with your openSUSE version). Please remove every other KDE repos that you enabled before:
# zypper ar -f http://download.opensuse.org/repositories/KDE:/Distro:/Factory/openSUSE_12.2 KDF
Now upgrade the all packages by running this command:
# zypper dup --from KDF
This will upgrade your current KDE to KDE SC 4.10 RC1. Optionally, if you want to install KDE extra tools than you can do so by following steps:
First remove the old instance of KDE extra with this command (replace 12.2 with your openSUSE version):
# zypper rr http://download.opensuse.org/repositories/KDE:/Extra/openSUSE_12.2/
Now add the KDE:Distro:Factory Extra repo to system with this command:
# zypper ar -f http://download.opensuse.org/repositories/KDE:/Extra/openSUSE_12.1_KDE_Distro_Factory/ KDF-extra. Now upgrade packages by running
# zypper dup --from KDF-extra
More information on upgrading KDE can be found on KDE upgrade wiki.