Can you enable SSH access? If so, you can use Terminal to SSH into the MBL and give it the commands to do a firmware reinstall.
If you cannot enable SSH access, then you will have to do a debrick process.
You can find the details for these actions on this forum in other threads.
http://mybookworld.wikidot.com/forum/t-307650#post-1003066
http://community.wd.com/t5/My-Book-Live/GUIDE-Debrick-MyBookLive-v2-0/td-p/567582
