Yes it will
If the 2TB drive is from another MyBookLive then you can swap it without issue
If this is a blank hard drive you will need to put the OS on the hard drive first, otherwise the MyBookLive won’t boot. I put together a couple of guides but this one is the easiest to follow
http://community.wd.com/t5/My-Book-Live/GUIDE-Debrick-MyBookLive-v2-0/td-p/567582