if you know what you do, why not, but prefer to choose cancel child records for all objects created stock picking, move, procurement ...) and create new sale order

@Mindhunmadhu.  Yes, you'll have problem if you change the value directly from the database because it will make the workflow of that particular sale order in foobar state (unless if you know how to fix this also).  @Cyril's advise to cancel the sale.order and recreate it, is the safest bet.