Remove bullet from Word FIle USing c#

HI,
 
How can i remove bullet from Winword 2007 using C#
 
here i have mention code below it will open word file using c#
 
object file = @"D:\SAMPLE QUESTIONS.docx";

wd = new Word.Application();
            document = wd.Documents.Open(ref file, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj);

wd.ActiveWindow.Selection.WholeStory();
           wd.ActiveWindow.Selection.Copy(); IDataObject data = Clipboard.GetDataObject();
           string text = data.GetData(DataFormats.Text).ToString();
           richTextBox1.Text = text;

 
can you help me for above issue its Urgent
 
Thanks
Vijay.S