You can try to use HTML Agility pack. This can be downloaded as a Nuget Package.
After installing, this is a tutorial on how to use HTML Agility pack.
The link has more info but it works like this in code:
var urlLink = "http://www.google.com/jsonPage"; // 1. Specify url where the json is to read.
var web = new HtmlWeb(); // Init the HTMl Web
var doc = web.Load (urlLink); // Load our url
if (doc.ParseErrors != null) { // Check for any errors and deal with it.
}
doc.DocumentNode.SelectSingleNode(""); // Access the dom.
There are other things in between but this should get you started.