First, you need to download plugin files and unzip downloaded archive to plugins directory. After that, you can rename plugin folder and main plugin file as you want.
Open main plugin file
example-plugin.php and change the meta data. You will need to enter data like plugin name, plugin URI, author name and so on.
Plugin Name: My Awesome WP Plugin Plugin URI: http://example.com/my-awesome-wp-plugin/ Version: 1.0.0 Author: Vladimir Anokhin Author URI: http://example.com/ Description: My Awesome WP Plugin Description Text Domain: my-awesome-wp-plugin Domain Path: /lang License: GPL2
Now you can edit code of the main plugin file. As you can see, there is already present code that performs plugin initialization and creating the options page. For more information about initializing see the class reference.