Change Object Number and Department
These two fields are accessible in the same widget, but you do not have to make changes to both when you are updating one.
Step-by-step guide
In the object hierarchy panel (left), click the down arrow in the top object level
Select Change Object Department / Object Number
Either select new Department or enter new Object Number
If you are changing the object number, be sure that Save the previous Object Number as an Alternate Number is checked
Click Apply to save changes