Simplify the following text for a Grade 10 native English-speaking person.
Original: Under the first stage , the Baker Street to Stanmore branch of the Bakerloo line was joined at Baker Street to a new 2.5 m segment into central London , with intermediate stops at Bond Street and Green Park and terminating at a new station at Charing Cross , thereby relieving pressure on the West End section of the Bakerloo line between Baker Street and Charing Cross and also allowing increased frequencies on the section north of Baker Street .
Simplified: To the Baker Street to Stanmore part a new four-kilometre part into central London was added , terminating at a new station at Charing Cross railway station .