Part of the plan means the No 3 bus will run between Trafalgar Square and Russell Square instead of going via Regent Street. The route between Crystal Palace and Trafalgar Square stays the same.
Similarly the N3 bus will no longer go to & from Oxford Circus but run between Russell Square & Trafalgar Square and then the usual N3 route to & from Bromley North.
For more details see: https://consultations.tfl.gov.uk/buses/bus-routes-3-137-and-n3/
The deadline for comments on the plan is Sunday 29th January 2017.