On OpenSolaris, you need to use the new IPS package manager commands to
remove the packages installed with the OS.
You should just have to run:
pfexec pkg uninstall NVDAgraphics
Though due to a bug in some builds, you may also need to run first:
pfexec pkg uninstall slim_install
(which tells the system to not require all packages installed by the LiveCD stay installed, and given the error you posted, seems to be affecting your system).