MyBookLiveDuo Fat32 Format Mac

I recently purchased the WD MyBookLiveDuo to connect to my Mac so I can create a cloud service from home. The WD drive needs to be formatted in Fat32 to enable it to be backed up to Time Machine however when I use Disk Utility to locate the drive to perform the reformat process the drive does not appear. It is key for me to be able to create a back up in Time Machine and I am told that this won’t be possible without reformatting to Fat32. How do I rectify this or is there another way to format the drive without using the Disk Utility?

You don’t need to change the format of the internal HDD, it should work fine with time machine. Follow the link below for the steps to map the my book and start a time machine backup. If you encounter any problems check if you have the latest firmware version.

Thanks for responding. I have connected to the drives and they appear on the finder and indeed on the desktop. All the latest versions of updates and firmware are also loaded. However when I go into Time Machine, the  drives are not coming up as highlighted because they are not being backed up. For some reason it is not backing them up even though they are mounted. It is from my google searches that I thought the key was to reformat the drive. Any other thoughts as to what the problem could be?