replacing the music in the prime time line

I am working on a music project with dozends of audio file in the prime time line and hundres of video clips joint to them.

Now I have re-recorded the music and want to replace all the old audio files by one new audio file (with a lenght of nealy two hours) but keep all the joint video clips joint to the original audio tracks. (of course I have to move them a bit to adjust them to the new music track)

How to proceed ?