How does one remove the nvidia driver and install nouveau ?

[gilpel at altern.org]

Michael Cronenworth wrote:

> Hint: Why do you have two device sections?

Well I do not have two device sections:

more /etc/X11/xorg.conf

==============================

# nvidia-xconfig: X configuration file generated by nvidia-xconfig #
nvidia-xconfig:  version 1.0  (buildmeister at builder62)  Tue Jul 28
19:48:57 PDT 2009

# Xorg configuration created by livna-config-display

Section "ServerLayout"
    Identifier     "Default Layout"
    Screen         "Default Screen" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "Files"
    ModulePath      "/usr/lib64/xorg/modules/extensions/nvidia"
    ModulePath      "/usr/lib64/xorg/modules"
EndSection

Section "ServerFlags"
    Option         "AIGLX" "on"
EndSection

Section "InputDevice"
    # generated from data in "/etc/sysconfig/keyboard"
    Identifier     "Keyboard0"
    Driver         "keyboard"
    Option         "XkbLayout" "us"
    Option         "XkbModel" "pc105"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/input/mice"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "Device"
    Identifier     "Videocard0"
    Driver         "nvidia"
EndSection

Section "Screen"
    Identifier     "Default Screen"
    Device         "Videocard0"
    Option         "AddARGBGLXVisuals" "True"
#    Option         "ConstantFrameRateHint" "True"
    SubSection     "Display"
        Modes      "nvidia-auto-select"
    EndSubSection
EndSection

Section "Extensions"
    Option         "Composite" "Enable"
EndSection

========================

and when I issue the

/usr/sbin/nvidia-config-display disable

command, as recommended in

file:///usr/share/doc/xorg-x11-drv-nvidia-185.18.36/html/chapter-04-section-04.html

I receive:

Segmentation fault

My card is a 9400gt 1024 MB.

Maybe there's a problem?