It's easy to do so and what you need is just a video converter program.
And I am glad to share this one with you:
Moyea Video Converter.
It's used to convert among various video and audio formats such as AVI, MPEG, WMV, MOV, WAV, MP3, AAC, etc.
I prefer the program as its after-sale service is wonderful. After I purchasing the program, their support center delivered an email for greeting and helping. How warm and kind!
So I think when choosing an appropriate program for ourselves, we should consider not only its quality, functions, but also its after-sale service.
By the way, its quality is good and there is no spyware.