How to Change the Order Increment ID and Prefix in Magento

http://www.warpconduit.net/2012/04/18/how-to-change-the-order-increment-id-and-prefix-in-magento/

UPDATE eav_entity_store
INNER JOIN eav_entity_type ON eav_entity_type.entity_type_id = eav_entity_store.entity_type_id
SET eav_entity_store.increment_last_id='XXXXXXXXXX'
WHERE eav_entity_type.entity_type_code='order' AND eav_entity_store.store_id = 'Y';