如何卸载JPanel面板

先新建一个JPanel类,之后我在主界面的菜单中使用以下代码,替换当前界面的面板,把新的JPanel类做的面板载入.

主界面中打开新界面的按钮代码:
public void MaddMan_actionPerformed(ActionEvent actionEvent) {
    this.remove(contentPane);
    manAdd man = new manAdd();
    this.setContentPane(man);
    this.show();
  }

新的JPanel类的代码如下:
import java.awt.*;
import javax.swing.*;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Mp
    extends JPanel {
  public Mp() {
    try {
      jbInit();
    }
    catch (Exception exception) {
      exception.printStackTrace();
    }
  }

  private void jbInit() throws Exception {
   
    this.setLayout(null);
    jButton1.setBounds(new Rectangle(145, 113, 81, 23));
    jButton1.setText("jButton1");
    jButton1.addActionListener(new Mp_jButton1_actionAdapter(this));
    this.add(jButton1);
  }

  JButton jButton1 = new JButton();
  public void jButton1_actionPerformed(ActionEvent e) {

  }
}

class Mp_jButton1_actionAdapter
    implements ActionListener {
  private Mp adaptee;
  Mp_jButton1_actionAdapter(Mp adaptee) {
    this.adaptee = adaptee;
  }

  public void actionPerformed(ActionEvent e) {
    adaptee.jButton1_actionPerformed(e);
  }
}
现在问题是,如何卸载这个载入的JPanel类做的面板?回到主界面,具体代码看附件.

不知道

各位高手进来看看呢,求助求助!