We've had a bit of an issue where a clients staff member has misunderstood a process and marked over 100 orders and shipped/complete. The client has asked if we can revert the order status (and state) back to New (Processing)? Be very handy if there's a bulk method but even a single order by order version would be better than nothing
Thanks in advance
Once the order has 'Complete' status, it seems to me, that there is no way to get the same order back to 'Processing' in backend.
You can go order-by-order, create credit memo offline and then reorder. This way current order will be closed and new one with the same details and 'Pending' status will be created.
Alternatively you can make changes with some queries (for tech experts at their own risk) or use extension. If you are interested in the second option, you can check Store Manager for Magento application that allows to bulk modify order status from any to any -
I guess you need it one-time, so you can do it free with fully-functional 14-day version that you can download from the link in my signature.
Thanks very much for the help
In the end, I paid a freelancer to code a custom bit of script to migrate it all back