Hello,
I've never messed with Elten's translator before. As for premium packages, you could either go to the Community menu, then My Account, then find Others in the category list, or you could go to the Community and then Premium Packages. Once you're in the Premium Packages list, select the package that you want with the Enter key, then press Tab to find the Buy button. From there it should be pretty straightforward.
Hope this helps!