Revert to old firmware

I wish I never updated the firmware on this drive. Has anyone figured out a way to revert to the old? Is it still available? 

WD does not have previous firmware for the MBL available for download.  Not sure if you can do a rollback, I suggest you to contact WD Support to verify this:

What did the update do to your drive?

I have noticed that some of the firmware updates change things on the MyBook Live, like configuration files and similar that persist between updates. Forcing a firmware downgrade might brick your MyBook Live.