Another way to approach this is to crowd source the process. Since the video is available on youtube, anyone anywhere could watch it and type out 30 seconds to a minute or two for you. If you had a blogger page, they could post the transcibed portions in the comments section. Or if done in several forums, then as responses to the initial request. Then once everything was done, it could be handed off to someone who could create the subtitle stream. (defining the sentences and how long/where they appear)
How to get people to help you out is what you're going to have to figure out. Explain who you are, your situation and your appreciation of SW. Once you've got the blog set up or multiple forum posts, or a facebook group, or a yahoogroup, etc., contacting SW people is the next task. Contacting TF.n or some of the other big SW sites (maybe if asked nicely a place like digg.com) might give you the kick off to get the ball rolling.
Is there a support group in the deaf community which might have suggestions on how to get transcribing done for media which doesn't have one?
Here's the first minute:
From Star Wars to Jedi: The Making of a Saga
Initial Transcript (requires proof reading)
Ten years ago, in a galaxy very very near. George Lucas imagined a world no one else had ever seen. When he placed it on screen in 'Star Wars', in 1977. He asked us to see it through the eyes of a restless and idealistic young man, Luke Skywalker.
Through three films, Luke would travel through the farthest reaches of his galaxy seeking adventure manhood and wisdom.
It would be a perilous journey, for this was a universe in turmoil. The forces of light and darkness, locked in mortal combat.
The dark lord of the Sith. Exemplar and symbol of all the evil Luke would have ultimately have to confront, Darth Vader.
A third option is to find a transcribing service (the medical profession uses them) figure out how much it would cost to do the 50 minutes. Pay that amount yourself or start a kickstarter page to get those funds. http://www.kickstarter.com/ Kickstarter is a place where you can suggest a project and if enough people pledge the funds when the mark is reached you'll have the funds to get the task done. Making the final transcript (and eventual subtitle stream) freely available on archive.org will help convince people of your goal.