You’ll have to do a bit of CS modification. I’m on mobile, so what I’ll say is just a general guide. Might do a detailed one once I got back, or maybe other folks can show you the way more detailed.
Find ui.js file (directory: …/web/); open it with text editor, preferably non-default ones: Notepad++, Atom writer, etc.
Find (Ctrl + F) for the text-elements you want to translate. Save the changes
Your future compiled games should utilize the translated elements.
