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Open all files and edit?...
actions/scripts
movements/scripts
creaturescripts/scripts
talkactions/scripts
I wont be saying where each file in the folder, since i guess your smart enough to know that "item" folder contains items, so open items.xml in item folder, and edit it... ctrl + f to find the item, and change to english...
if you dont know where is located certain file, post here a small info about what does the script do, the actionscript/uniqueid, and ill help you locate the file.