I used the mini boot install Debian disk
Here's the readme http://www.phy.olemiss.edu/debian-cd/README.txt
get it from http://www.phy.olemiss.edu/debian-cd/ I used woody-i386-1.iso
burn the iso to a CD
Stick it into your CDROM drive and reboot.
When it boots up I hit F3 to see my options and I picked to boot to 2.4
pick all of your options in the install to make your system work and a net driver

after the basic install you get onto the box and

if any of the apt-get stuff below says it can't find something then you may need to
add to /etc/apt/sources.list so you have some net site available with unstable main
like:
deb http://ftp.us.debian.org/debian/ unstable main non-free contrib
deb-src http://ftp.us.debian.org/debian/ unstable main non-free contrib

apt-get install -u kernel-source-2.4.19
apt-get install -u kernel-package
apt-get install debhelper dpkg-dev
get the text mouse installed for some copy and paste if need be
apt-get install gpm
cd /usr/src
bunzip2 the kernel tar.bz2
untar the kernel tar
ln -s kernelsource linux
cd linux
cp config from /boot to /usr/src/linux/.config
make oldconfig
make config
edit Makefile EXTRAVERSION=-YYYYMMDDn (put a real date and pick a number and put the -)
 to put a version on your new kernel so it doesn't interfer with other kernels and modules
make-kpkg clean
make-kpkg
make-kpkg kernel-image modules-image
dpkg -i kernel-image-2.4.19yournewversion.deb
lilo
reboot