Command blocks are generally restricted to creative mode users who are OPed. However, with this plugin, you are now able to legitimately craft command blocks and configure their commands (if you hold the necessary permission).
To update a command block's command, you will need to write and sign a book with the command on page 1. After creating this book, you just need to click the command block with the book in hand. It's as easy as that!
Command Block Recipe
Requires 4 redstone, 4 comparators, and 1 hardened clay.
Installation is very simple. After you download the JAR file, drag it into the "plugins" folder and reload your Bukkit server with the default /reload, which will then add the plugin to your server.
https:github.com/TNThieding/bukkit-legitimate-command-blocks\
