You can either upload the file to a site like youconvertit.com or zamzar.com or you can use the Flip4Mac player which will allow you to play them in Quicktime.
This has been something that has been giving me grief for a long time but was quite easy in the end. And free! Go to Sony UK website and then to mp3/music players. Go to 'contact' and it will guide...
You will need to convert the video. You can download a free video converter online. Google: free video converters. Select one you want, download and install it. Once you have a video converter...