"Maven is - at its heart - a plugin execution framework; all work is done by plugins."
This quote is the start of the Maven Plugins documentation. Thus, if you want to customize your Maven build project you should think about using a special plugin. If no plugin for your task is available you have the possibility to write your own.
To demonstrate how to write and document a Maven plugin I implemented the frvabe-maven-plugin. Have a look at the project itself and the detailed documentation which you will find beside the project on my GitHub page.