Follow these simple steps to uninstall the script (or before uninstalling the script using XScript Installer):
Load your savegame
Go to the Artificial Life setting menu ( [Esc] / General )
Locate “Pirate Guild : Intelligent Pirate Behaviours” and set it to FALSE
Wait until you receive a message telling that the plugin has been disabled
Save and quit the game
Delete files of this archive from the script folder (not really necessary, though)