1. Open Server app.
2. If you see a Welcome screen and a button named Configure, you have not yet set up Lion Server; quit Server app and skip to step 8.
Otherwise, if you don’t see a Welcome screen and a Configure button, continue to step 3.
3. Check the Services list on the left side of the Server app window. Select each one that is on (as indicated by a green dot) and flip the switch in the upper right from On to Off.
4. Click on the icon for your computer in the Hardware list, on the left beneath the Services list.
5. Click the Settings tab.
6. If the box next to “Dedicate system resources to server services” is checked, uncheck it. This will display a message telling you that you must restart your computer for the change to take effect. Click “Restart Later”.
7. Quit Server app.
8. Remove Server app from your Dock. You may delete it from your Applications folder, but it is not necessary. You may also remove the Server folder containing the advanced Server Admin Tools if you installed them separately.
9. You need to also delete: /System/Library/CoreServices/ServerVersion.plist . This is what tells the system that’s is a server version (and the one, if present, that allows install/startup in VMWare). After that, Software Update and others will work with /System/Library/CoreServices/SystemVersion.plist (which is ignored if ServerVersion.plist is present)
10. Restart your computer, if you were instructed to in step 6.
11. If you reinstall the Server.app and want it to start up fresh then remove /var/db/.ServerSetupDone