It might be in any number of places, depending on how Beth did it. If you are lucky, someone else here did this and knows where the relevant scripts are ... if not, then ...
You'll have to go through every stage of the CW Quests and figure out what is going on. It is very likely you will eventually find the name-changes in there somewhere
You will help yourself, if you have played (and remember well) the CW because you should be able to locate the relevant points in the chain-of-quests much more easily.
What you want to accomplish will probably be quite easy ... but as with anything that edits Vanilla, it will probably be a pain to get to that stage
(and note ... editing vanilla may give you compatibility problems with other mods ... though for this I would not think that too much of a problem ... names don't do much in game ...)