Dear,
You can edit the maintenance orders even after BUSINESS CLOSURE, & TECHNICAL CLOSURE and Even after confirmation of Operations.
But , you have to cancel all the BUSINESS transactions performed, i mean "Cancel Business completion" so that system will bring back the maintenance order to TECHO status.
Then cancel the "Technical completion" then system bring back the maintenance order to REL CNF status.
To cancel the Business and technical completion you can use even IW38 also.
Here select the multiple orders you need to revoke BUSINESS & TECHNICAL completion and click on select all-->Ordere-->Completion-->Cancel Business or Technical completion as shown in Fig.
If you cancel the operations system bring back the maintenance order to REL status.Use IW45 to cancel the maintenance order operation.
Then you can edit the Maintenance order operations and components and can receive Service entries with respect to Maintenance order etc...
Hope you got an idea.
Regards,
Pardhu