Question: How can I replace the last two matched string

`string s= "{\"test\":\"value\"}";`

From this string "s" I need to remove the double quotes of the value.

But I need generic, like the value may be any string in feature.

I need this to be done in `C#`.

Answer: 
This [example](http://answers.oreilly.com/topic/340-how-to-quickly-find-the-last-match-in-a-string-in-c/) shows how to search a string using regex from right to left. You might find it of use.
You could use [String.LastIndexOf](http://msdn.microsoft.com/en-us/library/system.string.lastindexof%28v=VS.71%29.aspx) and [String.Remove](http://msdn.microsoft.com/en-us/library/system.string.remove%28v=VS.71%29.aspx) methods:

```
 for (int i = 0; i < 2; i++)
 {
      s = s.Remove(s.LastIndexOf("\""), 1);
 }

```

It will produce String `{"test":value}` from `{"test":"value"}`, and I believe that's what you wanted to achieve.