There's no 100% code that I can give you but I found some reference articles
http://garfoot.com/blog/2008/06/transferring-large-files-using-wcf/
http://msdn.microsoft.com/en-us/library/ms733742.aspx
http://www.codeproject.com/Articles/166763/WCF-Streaming-Upload-Download-Files-Over-HTTP