Need Help [Media.PK2 Edit]

Dim fs As New FileStream("C:\Program Files (x86)\Silkroad\Media.pk2", FileMode.Open, FileAccess.Write)
        Dim br As New BinaryWriter(fs)
        Dim bytes() As Byte
        'IP1
        br.BaseStream.Position = "&H25F24011"
        bytes = System.Text.Encoding.Default.GetBytes(ip1.Text)
        br.Write(bytes)
        If ip1.TextLength <> 16 Then
            For i = 1 To 16 - ip1.TextLength
                Dim tmp As Byte = &H0
                br.Write(tmp)
            Next
        End If
        'IP2
        br.BaseStream.Position = "&H25F24026"
        bytes = System.Text.Encoding.Default.GetBytes(ip2.Text)
        br.Write(bytes)
        If ip2.TextLength <> 16 Then
            For i = 1 To 16 - ip2.TextLength
                Dim tmp As Byte = &H0
                br.Write(tmp)
            Next
        End If
        'IP3
        br.BaseStream.Position = "&H25F2403B"
        bytes = System.Text.Encoding.Default.GetBytes(ip3.Text)
        br.Write(bytes)
        If ip3.TextLength <> 16 Then
            For i = 1 To 16 - ip3.TextLength
                Dim tmp As Byte = &H0
                br.Write(tmp)
            Next
        End If
        'IP4
        br.BaseStream.Position = "&H25F24050"
        bytes = System.Text.Encoding.Default.GetBytes(ip4.Text)
        br.Write(bytes)
        If ip4.TextLength <> 16 Then
            For i = 1 To 16 - ip4.TextLength
                Dim tmp As Byte = &H0
                br.Write(tmp)
            Next
        End If
        'port
        br.BaseStream.Position = "&H25F24461"
        bytes = System.Text.Encoding.Default.GetBytes(port.Text)
        br.Write(bytes)
        If ip4.TextLength <> 5 Then
            For i = 1 To 5 - port.TextLength
                Dim tmp As Byte = &H0
                br.Write(tmp)
            Next
        End If
        br.Close()
        fs.Close()

br.BaseStream.Position = "&H25F24050"