Hi tombikadam,
.ppi files (Pack Install files) cannot be imported into YEM. You need the original .ppf file (Pack Project file) of this Pack to can do what you want.
The only thing you can do with this .ppi file is extracting the contained Styles using a PC program like "Style Extractor" or "Style in YEP/PPI file". But if the extracted Styles use Voices of that Pack, the Styles do not work correctly.
Best regards,
Chris