You got your video tapes digitized to mp4, great choice! Now how can you cut that section you don't need?
The easiest video editing software we've come across and have been using for years is the Cyberlink PowerDirector 15. This program is also so popular that there's Youtube tutorial videos for just about anything. At the time of this writing is about $50 and it'll beat most free video editing programs because those free programs have limitations such as a maximum video length or even placing a watermark across your video.
For editing mp3 audio tracks we recommend Audacity, this also happens to be free with again plenty of tutorials on Youtube.
Haven't gotten your tapes converted yet? We can help!