You can cancel and modify your bookings in the Resources and Rentals modules.
For changes to your Admin Bookings, see the following documentation: Cancel / Modify an admin Booking
You can always edit a contract that is in Draft state. If it was changed to the Pending Approval state, change it back to Draft and make the changes.
When a contract is in the Approved state, you can not change it directly in the contract. However, you can proceed through the Calendar in the Resources module.
RESOURCES > CALENDAR
1. Click on the reservation corresponding to the contract, in the calendar.
Note that, unlike for the admin bookings, you can currently make changes only for one occurrence at a time, because each booking is linked to an invoice item.
2. Click on in the Edit section of the Event Details window.
3. Make the desired changes in the Schedule section.
Since the booking is linked to an invoice, you must first cancel the item in the invoice.
1. Click on Cancel the invoice to delete this event. You will be automatically redirected to the invoice containing the selected booking.
2. Cancel the booking in the invoice, as with any other purchase.
For more details, see the following documentation: Cancelling a purchase and issuing a refund
Once the booking is canceled in the invoice, it will be automatically removed from the Calendar. Note, however, that the contract will not be changed.