https://github.com/bookfere/Ebook-Translator-Calibre-Plugin/wiki/English#installation

Ebook Translator is a plugin for Calibre. It can be used to translate newspaper issues:

1) You export EPUB file (Nook) from PressReader.

2) You import EPUB file into Calibre.

3) Plugin translates each paragraph with Google Translate and adds the translation after the paragraph.