is it possible to change the order status manually.
If it is possible how and where do i need to do it?
Thanks for your help.
That isn't possible (at least you want to change the data into the database).
Normally the next status for an Order is related with the current state (and the possible new status are fulyl related with the current state).
(If you need more clarification on status vs. state diffs you can take a look to this post: http://ka.lpe.sh/2012/04/21/magento-order-state-vs-status/ )