Opening all posts for comments

Is it possible to use the user-interface (front-end) part of WordPress to open comments on all posts in one (or two) clicks? I have many posts with closed comments which must have happened by mistake, and I want to make them all open comments.

Here’s the caveat: My host provider doesn’t give me ssh access into the database, so I can’t just run a simple sql REPLACE command. Therefore, I need a way to do this from the Administration Panel within wordpress.

Thanks!

I wrote up this quick plugin that updates all posts of type post to comment_status open on activation, it should work for you. you can immediately deactivate and delete it once you activate it that once.

<?php
/*
Plugin Name: update comment status
*/
function activate_update_comment_status() {
    global $wpdb;
    $wpdb->update( 
        $wpdb->posts, 
        array( 
            'comment_status' => 'open'
        ), 
        array(
            'post_type' => 'post'
        ), 
        array( 
            '%s'
        ), 
        array(
            '%s'
        ) 
    );
}
register_activation_hook( __FILE__, 'activate_update_comment_status' );