You should take it to a gunsmith, or mail it to Ruger. My vote is to send it to Ruger, unless a competent gunsmith with the right tools lives near you, and is willing to do the job cheaply. To do it yourself, properly, you'd need to buy the tools from Brownells or Midway.
Do not clamp the barrel in a vise, stick a pipe through the open frame window, and crank it that way. That's just a friendly warning, in case someone else suggests it. I've seen that suggested on other forums, but this is not a good thing to do to your revolver.