Students of the University of Lodz are obliged to do sworn translations of the documentation concerning their education from the countries where they did high school or Bachelor degree.
It is best to contact sworn translator directly. Here is the list of sworn translators accredited by Polish Ministry of Justice.
You have to choose the language and the city and try to contact the translator. Remember that they speak your language so you do not need to speak Polish to communicate with them.
If you are not sure what documents you should translate, contact your Students Office.