It is about 5 km by road from Belarus Station, the Moscow terminus for trains to/from Belarus (Minsk and Brest), Kaliningrad, Smolensk, and international destinations including Vilnius, Warsaw, and Berlin, to the Ulanskaya Hotel.
By taxi
Depending on the time of day, the journey by taxi will take about 25 minutes, and should not cost more than $20. If you prefer, you can pre-order a transfer with a driver to meet your train here.
By metro
By metro, take the brown circle line from Belarusskaya Metro Station and go two stops clockwise to Prospekt Mira Station. Change to the orange line and travel two stops south to Turgenevskaya. From there, the Ulanskaya Hotel is only five minutes' walk away.