How to create your own language

To create your own language in LiveAgent go to Configuration > System > Languages menu and click the "export" link next to the English language.

How to work with translation file

Please, use some simple (non-rich) text editor like NotePad, PSPad, Geany or Gedit to work with the file. Do NOT use Microsoft Excel since it will most likely destroy the formatting and encoding of the file. 
The file you exported can be divided into two parts. First lines are the header part, more exactly "meta data",  where you are supposed to change the values of highlighted fields:
The value of 'lang_code' , that is originally en-US, needs to be replaced with the ISO code of your language you are translating LiveAgent to.
The value of 'lang_name' is the name of your language in its own language. E.g. for Slovak language you would type 'Slovenský jazyk'.
The value of 'lang_english_name' is the English name of your language you are translating LiveAgent to.
The value of 'lang_author' is your name or name of your company.
When the meta data is changed you can go on with the translation.
As you can see in the image above, translated lines are marked with T;N at the end of the line (T stands for Translated in status column). 
Let's take a look at the following row:
"Clean Install";"Clean Install";"S";"";"T";"N"
If you wanted to translate it to e.g. Slovak, the row would be changed this way:
"Clean Install";"Čistá inštalácia";"S";"";"T";"N"
As you may see it is only the 2nd part of the row (the part on the right side of the first semicolon from the left) you are working with.
The most important thing is to maintain UTF-8 encoding throughout the translation process and also to  save the file in UTF-8 encoding

Importing the translation

To import click the "Import language" button at Configuration > System > Languages 
and then click "Choose file" and look up your translation file
Once you confirm the selection of the file the import starts automatically. 
Once your translation is imported, log out and in the log-in screen choose your new language and log in to use LiveAgent in that language.