Refactoring will only rename the rules & will not have any impact to the work objects. It is HIGHLY NOT recommended to run such tools in production environment.

This is something which is NOT recommended within Pega. Changing the class structure on the existing work objects which is NOT recommended & not possible OOTB.

If you feel that is something which you need to do for sure, probably you need to do something like below.

1) Don't rename the existing the class

2) Create a a new class structure as you desire

3) Point the new class to same database table

4) Do all respective changes to the required data instances (Workpool within AccessGroups, etc)

5) Built a logic within your application to display the old work objects with different class structure