如何删除保存在文本文件中的选定项目

Question

这段代码：

//Adds a user named server into the serverlist box
serverListBox.Items.Add(this.serverTextBox.Text);
//saves that user named server into a text file where the user can load the next time he/she uses the application.
string path = @"C:\\Public Key Pin\UserServerData.txt";
File.AppendAllText(path, this.serverTextBox.Text + "\n"); 

将用户名为server（在文本文件中插入）放在文本文件中。

现在如何从文本文件中删除所选项目？