How can i sent API frame to XBee (S2) Router using VisualStudio C#

How do i sent API frames to XBee Router Via C# program. I have been trying to find samples or tutorial online to get me started but to no avail.

InitializeComponent();
SerialPort port = new SerialPort(“COM4”, 9600, Parity.None, 8, StopBits.One);
port.DataReceived += new SerialDataReceivedEventHandler(SerialPort_DataReceived);
port.Open();

        port.DtrEnable = true;
        port.RtsEnable = true;
        byte[] buffer = new byte[1024];

This code is all ive found but it is only to open my coordinator Xbee port( I think) How do i sent API frame and get a reading from it?
Help greatly appreciated! Thank you

this is the mode that I send comands API for other xbee in C#

private void button11iron_Click(object sender, EventArgs e)
{
try
{

            byte[] bytesToSend5 = new byte[] { 0x7E, 0x00, 0x11, 0x17, 0x01, 0x00, 0x13, 0xA2, 0x00, 0x40, 0x49, 0xA0, 0xEB, 0xFF, 0xFE, 0x02, 0x49, 0x52, 0x01, 0xF4, 0x8F};
            Comport.Write(bytesToSend5, 0, bytesToSend5.Length);

            textBox2.Text = "TX: 7E 00 11 17 01 00 13 A2 00 40 49 A0 EB FF FE 02 49 52 01 F4 8F";
            textBox2.ForeColor = Color.Green;
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Erro no Comando !", MessageBoxButtons.OK, MessageBoxIcon.Stop);
        }
    }

change your adress zigbee. int this case i send the comand IR
that sends values ​​of samples every 500 milliseconds

hello can you explain more the exact location of the 16 bit address in your byte array , my xbee receiver has address of 02

where do i key in this - thanks in advance