To remove MAC OSX Lion Server completely , follow these steps one by one :
1- Download "TrashMe" and use it instead of native Trash.
2- Run TrashMe
3- Drag the "Server" application from application folder to the TrashMe box and delete all items.
4- Restart yor Mac
You'll see Server app again but be patient, go to 5th step
5- Run TrashMe again
6- Open finder, select your Hard Drive (not user's folder), goto /Library
7- Delete the "Server" folder again with TrashMe
8- Open Finder, select your Hard Drive (not user's folder) ,goto /System/Library/CoreServices
9- Delete serverversion.plist again with TrashMe
10- Restart yor Mac
11- Stop the Apache server using Terminal : sudo apachectl stop
12- Stop the PostGRESQL database server :
sudo launchctl unload -w /System/Library/LaunchDaemons/org.postgresql.plist
13- Stop the Server Performance Logging :
sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.ServerPerfLog.plist
14- Restart your Mac again and wait for your MAC OSX Lion to boot up completely
15- Check everything to work properly and then restart your Mac again and hold "option" to go to boot menu
16- select Recovery Disk and then use Disk Utility to verify/repair for both Permissions and Disk
Now, everything have rolled back to the state before installing Lion Server App
Enjoy your originals.