MigrationDecompression class to support this post: http://tech.trailmax.info/2014/03/inside_of_ef_migrations/

MigrationDecompression.cs

using System;
using System.Data.SqlClient;
using System.IO;
using System.IO.Compression;
using System.Data.Entity.Migrations.Infrastructure;
using System.Xml.Linq;
using MyApplication.Migrations;
using NUnit.Framework;


namespace MyApplication.Tests.Data.Migrations
{
    [Ignore("Only for manual execution. Not a test")]
    public class MigrationDecompressor
    {
        [Test]
        public void DecompressMigrationEncoding()
        {
            var migrationClass = (IMigrationMetadata)new MyMigration();
            var target = migrationClass.Target;
            var xmlDoc = Decompress(Convert.FromBase64String(target));
            Console.WriteLine(xmlDoc);
        }

        [TestCase("MyMigration")]
        public void DecompressDatabaseMigration(String migrationName)
        {
            const string ConnectionString = // connection string to DB with migrations
            var sqlToExecute = String.Format("select model from __MigrationHistory where migrationId like '%{0}'", migrationName);

            using (var connection = new SqlConnection(ConnectionString))
            {
                connection.Open();

                var command = new SqlCommand(sqlToExecute, connection);

                var reader = command.ExecuteReader();
                if (!reader.HasRows)
                {
                    throw new Exception("Now Rows to display. Probably migration name is incorrect");
                }

                while (reader.Read())
                {
                    var model = (byte[])reader["model"];
                    var decompressed = Decompress(model);
                    Console.WriteLine(decompressed);
                }
            }
        }
        
        
        /// <summary>
        /// Stealing decomposer from EF itself:
        /// http://entityframework.codeplex.com/SourceControl/latest#src/EntityFramework/Migrations/Edm/ModelCompressor.cs
        /// </summary>
        public virtual XDocument Decompress(byte[] bytes)
        {
            using (var memoryStream = new MemoryStream(bytes))
            {
                using (var gzipStream = new GZipStream(memoryStream, CompressionMode.Decompress))
                {
                    return XDocument.Load(gzipStream);
                }
            }
        }
    }
}