Did you know you can change properties for more than one item at a time?  For example, let’s say you would like to set complexity to medium for a large number of use cases.  First select the use cases that you want to change in the main list (either by shift-click, control-click, or mouse drag to the right of the name).  Then using the property window in the lower right corner, set the value of the complexity property to medium - all selected use cases will have their complexity set to medium.  This is true for any property that shows in the property window including release, preconditions, assigned to, etc. (on some fields, you will need to type in the value directly as opposed to selecting it from the dropdown list).

Something to note when you do a multi-select: the property window will only show the value of a property if all selected items share the same value, otherwise, it will be blank.  For example, if you select a use case with medium complexity and one with high complexity, the complexity property will be empty since they don’t share the same value.  But that doesn’t prevent you from setting the value, and once you do, it will show since the two use cases now have the same value.