Just a snippet that uses System.IO.Compression to copy the data from an embedded files to a string and send it to the console.

UnpackZipFile.cs

using System;
using System.IO;
using System.IO.Compression;
using System.Linq;

namespace CheckZipToString
{
  internal class Program
  {
    private static void Main(string[] args)
    {
      using (var zipStream = new FileStream("some.zip", FileMode.Open))
      using (var archive = new ZipArchive(zipStream, ZipArchiveMode.Read)) {
        foreach (var entry in archive.Entries) {
          using (var stream = entry.Open())
          using (var reader = new StreamReader(stream)) {
            Console.WriteLine(reader.ReadToEnd());
          }
        }
      }
    }
  }
}