I’m not sure if its in the same place but I would think if its not then its very near by. I went to victoria (bus station) then walked to victoria train station and the tube is there aswell. It was just round the corner. I was worried about getting lost cos I’d only been to london once before but I was fine. If you get lost you can always ask the people who work at the station.
Are you staying in a hotel the night before ba? thats what I did then taxi to hospital the day of ba. x