How do I use the Drupal 7 API to change ownership of a comment
This changes the comment author details using the core comment API:

$cid = 12; // e.g get from db_select
$comment = comment_load($cid);
$comment-&gt;uid = 1;
$comment-&gt;name = 'admin';
$comment-&gt;mail = 'admin@example.com';
comment_save($comment);


You could also do something similar with a Rules component for use with VBO.