That should work, but just in case it doesn't here are two other ways to do it.
I'm not sure about tweakui. I know you can void certain letters and keep the OS from using them, but not sure if it will change them, but a guy mentioned it in a thread I was reading so I thought I'd provide a
link to the Microsoft site to help.
Another site mentioned this.
It's freeware, but they say it gets the job done.