Unpack the X archive and install it by running:
make World
make install
make install.man
If make World fails with a gcc complaint (which it probably will) you will need to edit the xc/config/cf/linux.cf file.
Open the xc/config/cf/linux.cf file in a text editor and go down to line 287 which says #define StandardDefines -Dlinux LinuxMachineDefines LinuxSourceDefines
Below that line entere these five lines:
#define DefaultCCOptions -fsigned-char
#define OptimzedDebugFlags -O2
#define LinuxMachineDefines -D__powerpc__
#define ServerOSDefines XFree86ServerOSDefines -DDDXTIME -DPART_NET
#define ServerExtraDefines -DGCCUSESGAS XFree86ServerDefines
Now install X by running the same commands as before:
make World
make install
make install.man