Read notes inside to see what each does.
Code:
/*To make items that are No-Drop(No-Trade) Attuneable as well:*/
UPDATE items SET attuneable = 1 WHERE nodrop = 0;
/*To remove the No-Drop(No-Trade) quality and set items to Attuneable instead:*/
UPDATE items SET nodrop = 1, attuneable = 1 WHERE nodrop = 0;