It is possible to walk to the Kremlin from the Medea Hotel in around 20 minutes. Turn left out of the hotel and left again, then follow the street round to Pyatnitskaya Ulitsa. Turn right and walk across the Vodootvodny Canal and the Moskva River. Once across the river, turn left along the embankment under the Kremlin walls, and circle the fortifications until you come to the main visitor entrance in the Kutafya Tower, on the opposite side of the compound.
You can also take the metro from Novokuznetskaya (two minutes' walk from the hotel), and travel north one stop to Teatralnaya. Change there to the red line, and continue west one stop to Biblioteka im. Lenina, which can exited right next to the main visitor entrance of the Kremlin.
You can also take the metro from Novokuznetskaya (two minutes' walk from the hotel), and travel north one stop to Teatralnaya. Change there to the red line, and continue west one stop to Biblioteka im. Lenina, which can exited right next to the main visitor entrance of the Kremlin.