Matrix Icon / Button Movement

I'm working on making a game in JAVA. To be brief, the game is on a 6x6 matrix called "blocks[][]". The game has two players and the objective is to capture the enemies pieces by moving your piece onto there's. The players do this by moving one piece per turn either forward/backward (Vertically) or right/left (horizontal) movements. Essentially checkers without jumps.I'm not very far into the development process here. So far I have the game board created and the pieces load by clicking the "Start" button (handled by the refresh function). However I'm having a few problems... Namely moving the pieces effectively at the moment.

Right now there's a lot to do:

(1) - Implement a turn system,
(2) - Only allow a player to click their pieces (I've a validation function already in place to only permit valid moves [horizontal/vertical only]),
(3) - getting the pieces to actually "move" what I mean by this is a player selects the piece they want to move, then they select the spot they want to move to and the icon I have placed on the button is supposed to be added to the new square and the icon for its previous position is to be made null.

Please see the "actionPerformed" section to see exactly what I'm trying to do and hopefully as well see what I'm missing as to why it is not working at the moment... Also see under the Refresh function where I commented out the for loops to add the pieces. I did this because it was resulting in an ArrayOutofBounds error so I just wrote each spot out manually where I wanted them to start.

/* Ghosts *
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.border.*;
import java.io.*;

[code].....