Private Option: Best option if you prefer to do the walking tour with a private guide. Meeting point is the same as the regular tour.
Meet by the statue in the large square with two fountains and a tall column topped with a man. Look for the guide with a blue badge and a blue bag or black backpack. If you see a man on a horse, you're in the wrong square. For ride-shares, select Praça Dom Pedro IV in Lisbon (not Queluz)
Depending on the route.