actually what I did is:
1.
edit /etc/apt/sources.list, add one line:
deb http://free.nchc.org.tw/ubuntu breezy main restricted
2. apt-get update
3. run "apt-get install linux-image" to see the available kernels
4. assume it's "linux-image-2.6.15-20-686", then run "apt-get -d install linux-image-2.6.15-20-686"
5. then you will see a .deb is downloaded in this working directory, like "linux-image-2.6.15-20_686.deb"
6. then use "mkdir linux; dpkg-deb --extract ../linux-image-2.6.15-20_686.deb ."
7. you will get some directories, like boot/, lib/, copy all the files in boot/* to /boot/, and "cp -a lib/modules/2.6.15-20 /lib/modules"
8. chown root.root /boot/*2.6.15*; chown root.root -R /lib/modules/2.6.15*
9. mkinitrd -o /boot/initrd.img-2.6.15-10-686 -k 2.6.15-10-686
 then you have to modify /boot/grub/menu.lst, add the entry for 2.6.15-10-686