using System;

using System.Linq;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

        string json = @"{""Country"":""USA"",""States"":[""Chicago"",""Miami""]}";

        string newJson = Remove(json, "Miami");

​

        Console.WriteLine(newJson);

    }

    public static string Remove(string json, string keepState)

    {

        JObject jo = JObject.Parse(json);

        jo["States"] = new JArray(keepState);

        return jo.ToString();

    }

​

}

​

​