I think the obvious first step would be to plug the hard drive they are one now into a computer and see what sort of format they are in now. If the receiver hasn't done anything too funky with it, odds are you'll be able to transcode them to whatever format you prefer.
As a side-note, and not that I mind. But why is this posted on a hacking forum? First and foremost this seems like a question for the device manufacturer's support department. Failing that I'd still look for some satellite or video enthusiast forum before trying here. Or is it that there is a chunk of information missing from your post and you already know it's not easily accessible and you need someone to help with the reverse engineering of the device and/or video format?