There is only one way to reset an approved billing stage line to Planned, and that is to do it manually. The status of the staged billing line is displayed in the Status column in Staged Billing Profile.
The billing stage is unapproved and the status on the billing profile line is changed from Approved to Planned.
Staged Billing Profile
Customer Order
Customer Order Lines
Staged Billing Profile
Customer Order
Customer
Order/Order Lines
Customer Order
Lines
The staged billing profile window could be opened from the Navigator directly. It is equally possible to open the same window from Customer Order by selecting the appropriate customer order line and choosing Staged Billing Profile... in the Operations menu.