Enable/open comments on all posts of a content type When I created a content type, I chose to keep the Comments hidden. Now I have many posts of that content-type and I want to open the comments, which I did by editing the content type, but it did not open comments of any posts of that content-type.

How do I open comments on all the posts of a content type at once?

How do I remove that little help box under comments text area?
Or directly into the database with : 

UPDATE `node` 
SET comment = 2 
WHERE comment = 1


and

UPDATE `node_revision` 
SET comment = 2 
WHERE comment = 1


Where : Whether comments are allowed on this node: 0 = no, 1 = closed (read only), 2 = open (read/write).