Can I use a WD External HDD and use it on my Xbox 360 to save games?

I understand it can be done with an internal WD drive..but I have a current 160 GB WD HDD. I am wondering how I can do this. I heard you have to do a FAT32 in windows on your HDD and then follow some steps but I am unsure if its possible with my hard drive and I do not want to take the risk unless I am sure it will work.