Write the how-to use it here
Other examples of plugins that makes runnable wars:
jetty-console-maven-plugin
winstone-maven-plugin
executable-war-archetype
executable-war
executablewar (Android)
Kohsuke Kawaguchi's blog post on the topic:
http://weblogs.java.net/blog/2007/02/11/hudson-became-self-executable
Licensed under the MIT License.
Copyright (c) 2011-, Kohsuke Kawaguchi, Sun Microsystems, Inc., and a number of other contributers (see AUTHORS file for credit).
The wiki probably has the answers to any other questions you may have.