If you are on Windows, you'll need Adobe Digital Editions and you'll need to activate it. Then with ADE running, plug in your 505 and activate it as well. Then you can use eBook Library or ADE to move your ePub over to your 505. You can then use eBook Library to move the ePub into your collections.
Yes there is a way to remove the DRM from ePub. See
https://www.mobileread.com/forums/showthread.php?t=39423 for the thread on it.