From Lisbon airport take a táxi to:
“Castelo São Jorge, Rua Espírito Santo, Numero 2.”
From downtown Lisbon in ‘Praça Figueira’ take bus number 37 to the last stop (which is just outside the Castle entrance) then it’s a 3-minute walk through the castle arch up Rua Santa Cruz do Castelo to: Antiga Casa do Castelo. (You will see the name of the house on a green oval plaque on the wall).
The entrance is the first door on the right just up Rua Espírito Santo at number 2.
Parking in the castle neighborhood is restricted so it is best to park in the underground car park in Praça Figueira and take the 37 bus or a taxi up to the castle.