I recall it being referred to as Bazooka Joe's swear filter, but I may be wrong. I have not heard of an automated tool to edit it, but any text editor should do the trick. Just be sure you are using a text editor (and not Word or Wordpad). For that matter, just go old school and use edit (Start -> Run or just hold the Windows key and hit R). Tell the prompt to run "edit" (without the quotes) and the old school dos text editor will open. You can use the menu to load and save files and they will be saved as text files.
If you use Windows Notepad, make sure to select All file types both when opening and saving the file. Otherwise it has a bad habit of changing the file name by adding .txt to the end. Also be sure it saves as ANSI and not unicode.