I've had to do this in the past after receiving a dvd from a friend in the UK. I found
http://forum.videohelp.com/viewtopic.php?t=300144 as an excellent guide on what to do.
There are a few programs needed to do the job (most are freeware). Everything is explained very well step by step. The process took 8-10 hours to strip the audio, render the video to convert frame rates and screen size, and then mash the audio back into the movie file. All in all I'm happy with the way it turned out even on my first attempt.