how do i dubb over a MPEG file with an MP3 file?

[Beautiful Alone]

how do i dubb over a MPEG file with an MP3 file?

I have a MPEG file of a band but the sound is poor , I want put a mp3 file over of it and save it as a mpeg or some other type of video file

[reboot]

Demux in tmpgenc's mpeg tools, remux with your mp3 after converting it to .wav in something like Audacity or SoundForge.