On each translation page you will have a "Download translation" link.
Click that link and you will be asked about the download format.
Choose "MO format" and click "Request Download" button.
A link to the translation file will be send over email in about one or two hours.
For Romanian translations of Jokey, it will look like:
Download the file and copy it over the existent Jockey translation file from your system.
The filename will give you a clue about where to copy the new MO file.
sudo cp ro_LC_MESSAGES_jockey.mo /usr/share/locale-langpack/ro/LC_MESSAGES/jockey.mo