How can I remove the OSX server? I have installed a OSX server a long time ago for testing purpose. It shows up in my App Store



However I cannot install update on my iMac that's running El Capitan due to this error message:



I really want to remove it because apparently this package is preventing me upgrade to Sierra. Sierra installer requested this to be of latest version before proceeding any further.
As an admin, open the /Applications folder, and drag the Server.app icon to the trash. An alert should pop up, saying the the server will be shut down, and a bunch of uninstall scripts will run. Your data will still be in /Library/Server.

You can empty the trash or pull it back out, if you want to keep it.

Then you should be able to upgrade the OS in peace.