don't worry, it seems confusing at first but it's pretty simple. there are actually quite a few different ways of compiling the kernel, and some people do certain steps in different order and whatnot. i would recommend the method shilo posted just above, that will work great for the 2.6.x kernels. essentially, you have to create the .config file, then use that to create a kernel image (bzImage, which you rename vmlinuz), and the modules, then move the modules to /lib/modules/2.6.x, then move the kernel image to /boot, then edit lilo to include this new kernel you have lying around.

??? where's the make modules... how can you install something you havn't built?

I did in this order

Copy the bzImage to the /boot folder and name it vmlinuz-2.x.y where x and y are version number.

Copy the System.map to /boot folder under System.map-2.x.y
Copy the .config file to /boot folder under config-2.x.y

Then symbolic links in boot folder:

vmlinuz -> vmlinuz-2.x.y
System.map -> System.map-2.x.y
config -> config-2.x.y

You needn't update grub or lilo every time since your kernel is already pointing to vmlinuz.

Works!

Remember to make sure that you still have a method for booting a kernel that is known to work, though.

No problem for me since I have Debian already installed. So if I cannot boot Slackware, I can get into Slackware partition through Debian and restore the old kernel files

I figured. That's why I mentioned it. For the clueless guy who reads it and doesn't have a second OS installed.