Updating audio track

I make a video of a concert at which we had a couple of cameras from different angles. I get an audio track from the sound technician. At some point in time, when I have done the editing of the cameras and synced to the audio track, the sound technician will get feedback and make an updated audio file. The new audio file is exactly the same length (minutes/seconds) as the original file. I have tried removing the old audio file from the disk, putting the new audio file there and giving it the same name as the old audio file. I',m not sure if this works, it sounds as if the old audio is cached somewhere and the new audio is not used. Is there a better way to do this? I just want to swap my existing audio for a new audio file without having to edit anything in the production.