I will tell you how to uninstall both and reinstall the new one's only: (but this is on SuSE 8.1)
what you do is download the new ones to a know directory.
Reboot your machine into linux safe settings. (runlevel 3)
then login with root and do a yast.
install/remove software, search for nvidia and remove them all.
Then get out of yast, cd to the official nvidia drivers and type:
rpm -Uhv NVIDIA_GLX-1.0-4363.suse81.i386.rpm
rpm -Uhv NVIDIA_kernel-1.0-4363.suse81.i386.rpm
reboot and ready.
Dont forget this is the SuSE way what i know of. i hope you understand it a bit and do it the RH way.