Update Intel driver in existing Xorg X Server

Existing situation:

- ASUS P5G41T-M/CSM mainboard, Intel G41 chipset and onboard graphics controller
- Linux (Debian), Xorg X Server 1.4.0.90

This Linux needs an updated Intel Graphics driver in order to work with this mainboard.
This is a highly customized Knoppix (running from a readonly medium).

I would like to know if it's possible to update only the Intel graphics driver for the Xorg X Server, without having to update the entire X server. Hints:

- The first version supporting my chip is xf86-video-intel-2.7.0
- The last version still accepting my X server version (1.4.0.90) is xf86-video-intel-2.7.1.
- The X Server cannot be updated without a MAJOR ROYAL headache, for reasons of libc6 update calamity, so I WILL NOT TRY

So basically I only have two different intel driver versions I could try to compile for my existing x-server, 2.7.0 and 2.7.1.

What I tried so far:

- Built and installed libdrm-2.4.20
- Built and installed Xorg 2D driver xf86-video-intel-2.7.1 in /usr/local/xorg
- Added
ModulePath "/usr/local/xorg/lib/xorg/modules"
entry in xorg.conf in front of the existing entry:
ModulePath "/usr/lib/xorg/modules"
- Then I tried running "startx"

The result was this:
===================================================
X.Org X Server 1.4.0.90
Release Date: 5 September 2007
X Protocol Version 11, Revision 0
Build Operating System: Linux Debian (xorg-server 2:1.4.1~git20080131-2)
Current Operating System: Linux Knoppix 2.6.26 #1 SMP PREEMPT Sun Nov 1 21:27:07 EST 2009 i686
Build Date: 14 March 2008 03:20:12PM

Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
Module Loader present
Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Mon Jan 20 13:03:06 2014
(==) Using config file: "/etc/X11/xorg.conf"
(II) Module "ramdac" already built-in
(II) Module "ddc" already built-in
(II) Module "i2c" already built-in
(EE) GARTInit: Unable to open /dev/agpgart (No such file or directory)
(EE) intel(0): /dev/agpgart is either not available, or no memory is available
for allocation. Please enable agpgart
.(EE) [drm] drmOpen failed.
(EE) intel(0): [dri] DRIScreenInit failed. Disabling DRI.
(EE) intel(0): AGP GART support is either not available or cannot be used.
Make sure your kernel has agpgart support or has
the agpgart module loaded.
(EE) intel(0): AGP GART support is either not available or cannot be used.
Make sure your kernel has agpgart support or has
the agpgart module loaded.
(EE) intel(0): Couldn't allocate video memory

Fatal server error:
AddScreen/ScreenInit failed for driver 0

XIO: fatal IO error 104 (Connection reset by peer) on X server ":0.0"
after 0 requests (0 known processed) with 0 events remaining.
=======================================================

I'm not clear on something: do I have to recompile the agpgart and drm kernel modules?
I suppose in order to have the full functional driver I need to built the Mesa and 3D driver too.

I DID read the Intel Linux Graphics Driver Build Guide and it does not actually explain nothing about this:

=======================================================
4.4 Mesa and 3D driver

You can refer to http://wiki.x.org/wiki/Development/git for new building process and skip this section.
If you only need Intel driver, you can specify it when run autogen.sh by adding option:--with-dri-drivers="i915 i965".
=======================================================

What am I supposed to understand? What "new building process"? Building what? What does "Intel driver" mean? The 2D or the 3D or what?

All I want to know is:

Is there a way to replace the Intel driver (2D+3D) in my existing Xorg X Server without replacing the X Server?
If so, what are the steps?

Thank you all experts in advance