by derPavlov
http://dev.bukkit.org/server-mods/block-cannons-v1-1/
Copy 'Cannons.jar' into your 'plugins/' folder.
Load your server
Edit the newly created 'config.yml' in 'plugins/Cannons/' and set your preferences
Delete the folder called 'Cannons' in plugins/.
Delete 'Cannons.jar'