For the circumvention of epub drm, have a look at this thread
https://www.mobileread.com/forums/sho...ght=inept+epub.
However, you don't need to remove drm to send the ebooks to your reader and read them on it.
I assume you have authorized your reader when you purchased your books? If you didn't, you will probably need to open the sony software or the adobe digital editions software and plug in your reader, they will guide you through the authorization.