use in drupal 5.x

It is not recommended to use betterawstats with drupal 5 because it is a lot of third party code that would likely get loaded/parsed on every page view in (slowing the whole site down). Drupal 6 allows the third party php code to only be loaded/used when needed. However, if you want to back port it, most of the changes would be reverting the actual bawstats.module back to the drupal 5 format (you shouldn't need to modify any of the third party code).