And here is a short video showing what the dialogue sounded like before and after we dubbed it.
The dubbing process was done on a line-by-line basis. Our actors would listen to a piece of dialogue a few times to get a feel for the timing, then repeat it into the microphone. Once all the dialogue was recorded, I would then spend a considerable amount of time matching the timing precisely to the original. The lip-synching was achieved not by matching the sound to the picture, but by matching the sound to the sound. Piece-by-piece, I lined up the new dialogue with the original (one audio feed in each ear), stretching or squashing it accordingly, until they matched.
For a 53 minute film, that's quite a bit of work.