How to go to Christ the Redeemer from the center of Rio de Janeiro without a travel agency? 

To go to Christ the Redeemer from the center of Rio de Janeiro:
1) Go to the bus stop in front of 148 rue Riachuelo (4 reals or 0.8€)
2) get off at the "Largo do Machado" stop
3) Buy the shuttle tickets (90 reals round trip including the entrance to the park, 18€)
4) at the park entrance take the shuttle that goes to Christ the Redeemer
1 half day is more than enough to visit Christ the Redeemer