Please contact your material controller (for every plant it will probably be a different person) - each material controller can modify the existing relation for the adress change or the change in name.
Your MC needs to fill in a form called "RNC case" that they send to our implementation team, who will make it possible for you to select it in Shipit.
Please note the whole process takes about 2 weeks from the date of submitting an RNC case, therefore please ask your MC how the bookings will be done until new relation is implemented.