Views: alter data of a View of another module
You would create a module.  It only needs a simple modulename.info file and modulename.module file.

If you called your module 'mymodule', then in mymodule.module add the function:

mymodule_views_data_alter(&amp;$data) { 
  \\custom code
} 


Clear the caches and you should be good to go.

The hook system allows modules to interact with other modules code. By naming your function MODULENAME_views_data_alter you are telling Drupal that you want to take advantage of the hook HOOK_views_data_alter.