simply connetcted to the computer by using a usb cable and put files(videos) in the mp4 folder , if your mp4 doesnt read them find 3gpp videos (videos that you can see on the phone)
You can use software like Aimersoft Video Converter which I like best to convert the videos to the format that your MP4 support. Here's the link: http://www.aimersoft.com/video-converter.htmlMP4 video error
I use a converter for ipods. I use it for my ipods but ipods play mp4 so I'm sure it would work for your mp4...(or you might have an ipod..I'm not sure) :)
It's very simple to use with clear instructions.
Here's the link to download it :)
You need to download a converter that converts the file to an mp4 or wateva it is you want to convert it to. Then you should be able to put them on your mp4. Hope that helps you.