Just download the image file,
This is code I grabbed off the internet
private void writeImage(string imageFilePath){
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(imageFilePath);
request.Timeout = 5000;
request.ReadWriteTimeout = 20000;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
System.Drawing.Image img = System.Drawing.Image.FromStream(response.GetResponseStream());
Response.ContentType = "image/gif";
img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif);
}
[edit]
if you want a more detailed answer, show me the object in the WSDL file from fedex, just paste the object details in.