Direct string hack of Revolt.exe is a method to have a working full custom track in Re-Volt without the use of patches or launchers. This method was created by Kfalcon and has been used in the creation of Re-Volt mods. Currently, no full custom track is using this method.
A string in Computer Sciences is a word (characters assembled).
Using a program similar to Microsoft Notepad or Notepad++, search for known strings (words, such as "nhood1" etc.). Note that the string/word "nhood1" is composed by 6 letters, that means you'll have to replace it by another word with 6 characters (such as "revolt"). And that's how you do for wavs, levels, and other files: by direct edition of the words, phrases, paths, values, and so on.