A challenger (I mean, helper) approaches!
Search for arc_conv and use that to extract the Data.wolf file. You'll get all the data files - put those in WOLF RPG's "Data" folder, and when you open up the editor, you should have be able to edit the stuff. (I don't understand why there isn't a proper "Project Open" option…)
Then when you're done, select "Create Game Data" from the file menu and choose the second option, "Encode Entire Data Folder," to get it compiled into a Data.wolf for release.