File extension changing

I can’t remember how to change a file extension from txt to xml. I have to do this to get dvdfab to recognize the profile. Im sure its something right in front of me. I’m runnin vista if anyone needs to know. Thanks for any help.

You just rename it. Be sure to turn on the file extensions.

Open “Computer” and press the alt key. In the menu that appeared click Tools->Folder Options.
Change to the tab named “View” and untick “Hide extensions for known file types”.