From Rio de Janeiro International Airport:
Take omnibus 2018 from REAL.
It takes approx. 40 mins to Copacabana beach.
Take off at Avenida Atlantica, it's easy to spot because it is the long promedade of Copacabana with the sea and beaches on the left hand side.
And just next to 'Rio Othon Palace Hotel'.
Alternatively, take a taxi that will take you to the apartment in about 30 minutes, for about 80 reais local currency.