There is already a Turkish language file available on http://lang.cPanel.net available for use.
However, if you are interested in creating your own translation, we have made it easy for you. Here's what you would do if you wanted to translate the cPanel and WHM into a foreign language, for example Turkish:
1. In WHM, on the left side of the screen scroll down to the "Languages" section and click the "Clone/Create a New Language" link.
2. On the right side of the screen, click "English" and follow the on-screen instructions being sure to give the language a name, let's say "Turkish" for this example.
3. On the left side of the screen (you may need to scroll down some more), click "Edit a Language File." This page will take a while to load.
4. On the right side of the screen, you will see every phrase that needs to be translated into Turkish in English in the center column. In the right column, you will see text boxes already filled with the English translation. You would delete these entries and replace them with the Turkish translation of those phrases.
5. Remember to click the "save" button at the bottom of that page periodically so you do not lose your work.
If you want to share your translations with the rest of the cPanel user community, simply follow our instructions on the above web page for submitting your translation.