CompDude is right...
Don't REPARTITION whatever you do. Keep fdisk/diskdruid away from your pc..
Download, unpaxk the files. enter the directory,,,
make menuconfig
make
(you can add "make modules" and "make modules_install" if you're not very paranoid about getting eveything in it's place)
cp arch/i386/boot/bzImage /boot/"bz2.6.5" (or what you want to call it...
then edit /etc/lilo.conf
and look at the entries at the bottom
# Boot up Linux by default.
#
default=2.6.5
image=/boot/2.6.5
label=2.6.5
image=/boot/2.6.4
label=2.6.4
Then save and run the command "lilo" and check for error messages...
Then Grab a beer and reboot the pc