Switch to a console with alt+ctrl+F1 (until F6)
F7 is the X-Server on most systems.
- login as root
- switch to a non-graphical runlevel with init 2 (until init 5, init 0 is halt, init 6 is reboot)
- rmmod nvidia (if old driver module was loaded)
- sh NVIDIA-Linux-x86-1.0-9746-pkg1.run (type sh NV and use autocompletion with TAB)
- you will be guided through the installation process