After my NAS ( old WD My Book World II.) stopped working about 2 months ago, I tired many different scenarios to retrieve my data from the internal HDD. Unfortunatley because the HDD was Linux Ext3 format, I failed many times until I learned about Ext2Fsd tool (http://www.ext2fsd.com/). I downloaded/Installed this tool on a Windows PC and after connecting my Ext3 HDD by using an external SATA-USB enclosure, I was able to read the data via Windows Explorer and copy the data from the Ext3 HDD to My Passport.
I am sharing this info in case there are others who may have the same need.