How to alter an existing Views display?
Views provided by a module are defined using hook_views_default_views - and as almost anything, they can be modified using &quot;alter&quot; version of this hook, namely hook_views_default_views_alter:
Alter default views defined by other modules.

This hook is called right before all default views are cached to the database. It takes a keyed array of views by reference.
Example usage to add a field to a view:

$handler =&amp; $view-&gt;display['DISPLAY_ID']-&gt;handler;
// Add the user name field to the view.
$handler-&gt;display-&gt;display_options['fields']['name']['id'] = 'name';
$handler-&gt;display-&gt;display_options['fields']['name']['table'] = 'users';
$handler-&gt;display-&gt;display_options['fields']['name']['field'] = 'name';
$handler-&gt;display-&gt;display_options['fields']['name']['label'] = 'Author';
$handler-&gt;display-&gt;display_options['fields']['name']['link_to_user'] = 1;

Source code from API help page linked above.