Every single english phrase in the program would have to be translated to make a language pack.
1. Go to admin panel and under language tab create a new language answer everything correctly charset etc. That will clone all your english phrases for the alternate language.
2. Go to admin config settings and set your global language to the new language you created say russian etc.
3. Go to admin language settings and view all phrases. You must make sure you set your global language to the new language and so when editing you will edit the current language strings. You will see all phrases and can edit each phrase as you see fit. Everything is paginated and easy to see.