between 3D AVCHD video and regular AVCHD video. The camcorder happens to have two lenses next to each other and the two images are recorded to the single storage media.

You did not tell us anything about the computer (we can guess it is Windows of some flavor) or the versions of Premiere, Vegas or Pinnacle Studio you are using. Assuming they are versions that were designed to deal with AVCHD files, then connect the camcorder to the computer with a USB cable and import or Capture as you would regular AVCHD files.

If the MTS video files have been copied to the computer, then you need to transcode them to something your editors prefer. HandBrake and MPEG Streamclip should work just fine. Again, this is no different than regular (non-3D) video files.

After the files are converted, bring them into your video editor, edit, export or share...