In case you require to modify a shift that has been mistakenly confirmed.
You need to follow the below instructions -

1. Open Finance Module 

> Select Invoice
> Change Invoice processing date to latest date 
> Click submit dockets.

2. On this screen



> Expand the Service location for which you need to change the shifts by clicking the "+" icon on left. 
> Here delete the docket that needs to be corrected.
> Close the window.

The deleted docket has been now moved to the confirm shift screen.

3. Open Confirm Shifts

> Click process booked shifts, you will notice that the shift deleted from Invoicing section appear here now.
> Select the shift that needs correction
> Review and validate it > do changes as required.
> Click Validate.

This is how you can correct a wrongly confirmed shift.