What steps do I need to take in order to change the 'look and feel' of java swing GUI?
UIManager.setLookAndFeel("com.jtattoo.plaf.acryl.AcrylLookAndFeel");

public static void main(String[] args) {
    try {
        UIManager.setLookAndFeel("com.jtattoo.plaf.acryl.AcrylLookAndFeel");
    }
    // Probably want to break this into handling the various exceptions that can be thrown.
    catch (Exception e) {
       // handle exception
    }

    // Create Swing GUI and so forth
}

import org.jvnet.substance.SubstanceLookAndFeel;

public class Main {

    public static void main(String[] args) {
       /*Si no se tiene instalado la libreria Substance*/
       //formpadre fp= new formpadre();
       //fp.show();

        /*si la libreria substance esta instalada y configurada*/
        EventQueue.invokeLater(new Runnable(){
        public void run(){
            try{
                JFrame.setDefaultLookAndFeelDecorated(true);
                SubstanceLookAndFeel.setSkin("org.jvnet.substance.skin.BusinessBlueSteelSkin");            //SubstanceLookAndFeel.setCurrentTheme("org.jvnet.substance.theme.SubstanceAquaTheme");
            }
            catch(Exception e){
            }
            new formpadre().setVisible(true);
        }
        });
    }
}