How do I save an edited pdf?

I would like to save a edited pdf template. How do I do that?

using (MemoryStream ms = new MemoryStream())  
{    
    PdfReader reader = new PdfReader("~/Content/Documents/Agreement.pdf");
    PdfStamper formFiller = new PdfStamper(reader, ms);
    AcroFields formFields = formFiller.AcroFields;
    formFields.SetField("Name", formData.Name);
    formFields.SetField("Location", formData.Address);
    formFields.SetField("Date", DateTime.Today.ToShortDateString());
    formFields.SetField("Email", formData.Email);
    formFiller.FormFlattening = true;
    formFiller.Close();
}