Changing data should be easier in WeBWorK 2. For each bit of information, it has a notion of the default value, and then the default can be overridden for an individual student.
The starting point for all of these operations is the Instructor
Tools page. It has two lists, one of all the students, and one of all
the problem sets.
Edit one set" on the right side.
Edit one set for one user" at the very bottom.