Here's a quick rundown of the days.
Trafalgar Square, Leicester Square, Chinatown, Covenant Garden
Sightseeing tour: Grosvenor Square, Hyde Park, Big Ben, Houses of Parliament, Tower of London, London Bridge & St. Paul's Cathedral. Changing of the Guard. Free time.
Guided excursion to Oxford and visit the University.
Eurostar Train through English channel to Paris then a bus tour of Paris; Arc de Triomphe, the Chemps-Elysees, Eiffel Tower, Ecole Militaire, the Opera Garnier, Place Vendome. Followed by a walking tour of Montmartre and a hilltop community once home to Picasso & Van Gogh