Anonymize comments after one year

I don’t have a ready to use solution. Howeder I think is not to heavy to build a custom plugin, that do that.

1. Update the comment data, use wp_update_comment().
2. For anonymize the IP you can use wp_privacy_anonymize_ip() (currently not in core, open as ticket).
3. Use the wp cron to run this after 6 months and build a comparison with the comment date to anonymize the data of the comment.

Alternative to the wp function to anonymize the IP helps this small function, only an small idea.

function fb_cut_ip( $ip, $cut_end = true )
{
    return str_replace(
        ( $cut_end ? strrchr( $ip, ':' ) : strstr( $ip, ':' ) ),
        '',
        $ip
    );
}