What field in your record are you currently putting the translated by authors? That is the field name you would replace “Translator” with. I tested putting the translator in the “Translated Author” field and it seemed to work fine. I am really not sure how that field would normally be used anyway, but it will not be intuitive for anyone else (or even for you a year down the line!). Your version where you copied the text over should need to change the word Translator to Translated Author.
Alternatively, you can go into the preferences, ref type, modify ref type, end add “Translator” to the subsidary author field space which is currently empty. This will solve it for you, but your class mates would need to do the same (or you can export your ref type file and they can import it, but that is probably more complicated than making the change themselves). Then you can use the field name “Translator” just like in the other reference type. This is the cleanest option, and will make sense to others, but requires more steps.
The output styles that you have downloaded or the one you saved from me, are saved by endnote in a user set in a folder defined by your Endnote preferences, folder location. You could search for the file name.ens to find the location. You share that file and when they open it, and save it, it will save it to a their “folder location” and Endnote will find it when you view the styles (it combines the folder that contains the endnote installed styles with those the user downloads or edits and then chooses “save as”).
You can just email it or drop the file in a shared folder anywhere.