Well, it's a bit complicated, but posible with NI to change this in a saved game:
- open the Baldur.gam in the savegame-folder, from the savegame, you wish to change with NI
- click on the creature, you wish to change something - in this case *halid in the list in the right above corner and click the "View/Edit" Botton
- in the appearing window scroll down and doubleclick the las line with the Creature mentioned in it
- here you will have the Creature file as it is saved in the running game
- again scroll down at the botton of this creature file
- here you will find many lines called "Modifying profiencies (233)"
- look at them by click on them to fine the one you wish to change
- if you have found it: doubleclick on it and choose the line with the "PROFIENCYXXXXX" - under it a scroll window will appear, where you can choose another Profiency.
- choose one and click the "Update" botton
- clos the little window and click "Save" in the Creature.file
- close all open windows (except the mainwindow of course)
- Save the .gam
I think, you will manage it, if you know how to handle NI
Have Fun