Charing Cross
Get the Jubilee Line train to Baker Street and then the Metropolitan, Hammersmith & City or Circle Line to Euston Square.
North Greenwich Underground station on the Jubilee Line is the easiest one
London St Pancras International Station.
Paddington
St.Pancras
London Paddington.
Take the London Underground (the Tube) on the Jubilee line to North Greenwich.
the London train station
The busiest train station in the UK is London Waterloo.
Take a train from London Waterloo station.
train from guildford station to London Waterloo
Travel from Lancaster to London Euston with Virgin Trains, then take the London Underground's Northern Line (Bank branch) southbound to London Bridge, and then the Jubilee Line eastbound to North Greenwich for the O2.