Java Recursion Word Pyramid?

I was asked to create a word pyramid program using recursion. I understand the concept of recursion (i.e. a method calling itself with the problem it is solving getting simpler and simpler each time) but I am having issues writing the program. Here is my code:

public static void main(String[] args) {
//This program will create a word pyramid by using a recursive algorithm.
//For example, the output of "DOGGY" should be:
//DOGGY
//OGG
//G
//This program will also use a recursive algorithm to accomplish this.
String userWord = JOptionPane.showInputDialog(null, "Hello and welcome to the Word Pyramid program."

[Code] .....

So, if I input HORSE the output should be:

HORSE
ORS
R