First, go into System Preferences.
Next, click on the FlexCal icon at the bottom of the System Preferences pane.
Uncheck "Start FlexCal at Login".
Go back to the main System Preferences area.
Hold down CTRL on your keyboard, and click on FlexCal.
Click on "Remove "FlexCal" Preference Pane".
FlexCal will now be in the Trash. Empty the Trash at your convenience.
To remove preferences for FlexCal go to your home directory, then to Library, then to Preferences
Remove any file in there that starts with com.flexgames