You can update manually by going into the MyBookLive UI > System > Updates > Update from File
Here is the download link for the latest Firmware, 02.43.10-048:
http://download.wdc.com/nas/apnc-024310-048-20150507.deb
Once it’s downloaded, select it after clicking on “Update from File”
I updated a few weeks ago and since then I have had an issue with the device being unable to sleep.
Another person reported a similar issue here
Not sure if it’s definitely caused by the latest firmware or another factor but just a heads up incase your device happens to be the same after updating.