Back down to the room and straight ahead to a lift bubble. Hit the button to go down. Exit to the guarded chamber and turn right. Either stun the guards with GEBs or Force push them. Go straight ahead and turn left.
Force push the guard and go ahead and then right.
Chat with the friendly Gungan and be sure to get the Otoh Gunga Pass from him. Go right past the little boy to enter a large room. Pedestals lift from the floor as you approach. If you miss, the guard below will attack. Force push him if necessary.