Can I convert a purchased epub doc to pdf form for commenting?

I bought a book with the purpose of commenting/highlighting on a large-screen PC rather than a tablet.  The sample it allowed me to download was in PDF form, & allowed me to highlight & comment, so I went ahead & bought it.

However, the purchased product is in ePub format, and does not allow commenting & highlighting.  Is there a way I can convert from ePub to PDF so I can achieve my original purpose?  (I doubt I'll get a refund....)