How to change WSDL in asmx into ASP.Net ?

Hello


Actually I have one ASMX service that return image in byte array.
That works fine with small size image but when images is too large like above 100 MB or more
that time my service client can't handle it and fired the error.
I googled and found like to put "xmime:expectedContentTypes" element property like below in WSDL
 <element name="ImageData" type="xsd:base64Binary"
           xmime:expectedContentTypes="application/octet-stream"/>

And if we needs that property then we need to change WSDL and put below tag in WSDL.
    " xmlns:xmime="http://www.w3.org/2005/05/xmlmime "

For example
<wsdl:definitions xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:tm="http://microsoft.com/wsdl/mime/textMatching/" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:mime="http://schemas.xmlsoap.org/wsdl/mime/" xmlns:tns="http://tempuri.org/" xmlns:s="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://schemas.xmlsoap.org/wsdl/soap12/" xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" targetNamespace="http://tempuri.org/">

to change it like

<wsdl:definitions xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:tm="http://microsoft.com/wsdl/mime/textMatching/" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:mime="http://schemas.xmlsoap.org/wsdl/mime/" xmlns:tns="http://tempuri.org/" xmlns:s="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://schemas.xmlsoap.org/wsdl/soap12/" xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" targetNamespace="http://tempuri.org/" "xmlns:xmime="http://www.w3.org/2005/05/xmlmime">

So Is there any mechanism to change it.

Thanks
Harshad