Handbrake is all you need, you can download it here for free – https://handbrake.fr/downloads.php
Once you have that installed and running you can do the following to convert your .vob files to .mp4
1. After downloading Handbrake for Mac, Windows, Linux, open Handbrake.
2. Click the “Open Source” button to add the VOB file you’d like to convert to MP4.
3. Move your mouse to the “Preset” and choose a desired one. Navigate to the “Summary” tab, click the drop-down menu of Format and choose MP4.
4. Select the output path where you want to save your new MP4 file by clicking the “Browse” button.
5. Now click Start Encode button at the top of the main Handbrake window to start converting VOB video file to MP4 format.
Let us know if you have any questions.