Well, as an example, I was having trouble with the chat bubbles: I had converted over all the fonts files, and all the non-quest chat bubbles were still using Times New Roman.
So, I ran windows search for "*.xml" in "E:\EQ2\UI\default" containing the text "Chatbubble", and it came up with eq2ui_proxyactor.xml.
So yeah, just search the files for text that will appear in the window and it should bring up what you need. If you're still having trouble you can make a post in the forums here asking what the XML file is for a given window, and someone will (probably) find it for you.
