patch

These instructions assume a GNU-Linux, Mac OS X, or other UNIX-y computing environment.

Follow these instructions for using CVS:

http://drupal.org/patch/create

However, if you are making a patch for a contributed module rather than Drupal core, going to the Drupal root directory doesn't make sense.

Following the Drupal documentation on applying patches.

The module localization client, originally developed for Drupal 6, needs a patch to the Drupal core module, locale (note that while locale is core it is also optional and disabled by default).