It's really simple. The biggest thing needed is the right software.
There are three software packages that I've used that would accomplish the video portion of the task; DVD Lab Pro, Sony Vegas, and Adobe Premier. There are I'm sure many others out there, but these are the three that I know of...DVD Lab Pro is easiest to understand and use, followed by Vegas and then Premier. I think it's probably safe to say that DVD Lab Pro gives really nice results, but maybe less 'professional grade' than the other two packages.
OK, next question is whether or not the video is a multiple camera video. If it's just a single camera shot video, then this job is even simpler. If you're doing a multi-cam, it's not all that much more difficult, but just requires more steps.
(For a single cam video, I'd recommend using DVD Lab Pro since it's so dang easy to do. This is the software that I use most, so I'm most familiar with it. I'd have to beleive that the others are just about as easy to use as DVD Lab Pro for such a basic job. If I have a multi-cam video to make, I do the video editing in Vegas....DVD Lab Pro really isn't made for that task.)
So, here's what you do with a single cam video.
1) Use DVDLab, Vegas or Premier to strip the audio from the video (called Demuxing or DEMUltipleXing). After demuxing, you should have three files, the original mpeg video file, a .mpv video only file, and a .wav audio only file.
2) Open the stripped audio in an audio mastering software program, such as Adobe Audition, Wavelab, or Soundforge.
3) Open the SBD file in the audio mastering software.
4) Using the stripped audio as a basis, make the SBD file timing exactly the same as the stripped audio file. Here's how I do this...
a) First I go through both files and compare them to see if there are any major differences between the two files, such as drop-outs, early starts, late cuts, stoppages during the encore break, etc.
b) Compare the timing of the two files to determine if the SBD needs to be stretched or shrunk to match. I do this by choosing a continuous run of music that exists on both the SBD and the stripped audio. I then select two distinct points in the music (usually a drum hit) at the beginning and end of the sample (the longer the sample the better). Use the software to shrink or stretch the SBD audio to match the stripped audio.
c) The goal is the match the SBD audio to exactly parallel the stripped audio, therefore, any dropouts (hopefully none) on the stripped audio need to be also made on the SBD audio.
d) I've had some instances where there was a drop-out in the video and I decided to leave the SBD audio intact and add space in the video rather than forcing the drop-out into the master video. I do this by inserting either supplemental video (it might not match, but it's better than watching nothing while listening to the SBD audio) or I insert a slide show of some kind...either screenshots of the same video or stills of the band from either that show or another.
e) Don't forget that after getting everything snynched up right, you also want to make sure that the end of the SBD file is also at the same spot as the end of the stripped audio...so that your master audio exactly matches the length of the master video.
4) Once you get the two audio files to match exactly, you no longer need the audio file that was originally stripped, although I wouldn't trash it just yet. Remux the SBD audio with the video file.
5) After the remuxing is completed, you will obviously want to check to make sure that the SBD audio synchs up with the video properly. Check every several minutes throughout the video.
6) If the audio and video aren't properly synched, tweek the SBD audio file however necessary to fix the synching. In my experience, the audio and video are usually well synched the first time, however I have had instances where I needed to tweek the master audio a little bit. These include;
a) shifting the start of the audio plus or minus a tenth or two to make the entire track synch properly (do this by adding or subtracting from the start of the SBD audio...usually all that's needed is a tenth or two.)
b) doing another stretch/shrink if needed.