From Liverpool Street, where most of National Express and Terravision buses arrive, take the underground via the Central Line (westbound) to Tottenham Court Road and once there follow the same instructions as above.
The other major bus station is Victoria bus station. From there, head to the underground and catch the Victoria Line (northbound) to Oxford Circus. Once there follow the same instructions as above.
From airports: From Heathrow Airport take the Piccadilly Line underground directly to Leicester Square tube station. Once there, follow the same instructions as above.
From Gatwick Airport, you can catch a bus or the Gatwick Express train directly to Victoria station.
From Stansted Airport, you can either catch the National Express or Terravision buses or the Stansted Express directly to Liverpool Street station.
From Luton Airport, you can catch the train from Luton Airport Parkway station, close to the airport with regular free shuttle connection. Otherwise you can catch a Greenline bus service just outside the Luton Airport to Victoria Bus Station.
From London City Airport take the DLR train to Bank Station and then proceed via Central Line towards Tottenham Court Road tube station.