using Newtonsoft.Json.Linq;
public static void Main()
""ResponseType"": ""VirtualBill"",
""DocumentId"": ""MN003_0522060"",
""ConversionValue"": ""1.0000"",
""BillType"": ""Vndr-Actual"",
""AccountDescription"": ""0522060MMMDDYY"",
""AccountLastChangeDate"": ""06/07/2016""
JObject jo = JObject.Parse(json);
JObject header = (JObject)jo.SelectToken("Response.BillHeader");
header.Property("ConversionValue").Remove();