using System;

using System.Text.RegularExpressions;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

        string invalidJson = @"

            {

                ""Field1"" = ""Hello"",

                ""Field2"" = ""Stuff = something"",

                ""Field3"" = ""I am non-Json Json, fear me"",

                ""Field4"" = 8

            }";

        string validJson = Regex.Replace(invalidJson, @"(""[^""]+"")\s?=\s?", "$1 : ");

        JObject jo = JObject.Parse(validJson);

        foreach (var prop in jo.Properties())

        {

            Console.WriteLine(prop.Name + ": " + prop.Value);

        }

    }

}

​