How to change Kubuntu Desktop into Server

If you have kubuntu 7.10 Desktop and want to make it server without reinstall the system then you need to install the server kernel, install the services you want your server to run (e.g. mail, web, db ... whatever) and remove desktop applications you don't need. Better if you installing the latest server edition. It is LTS afaik. You can always put kubuntu-desktop on there later with:
sudo apt-get install kubuntu-desktop