FAT32 has a 32GB patrition size limit. What you are trying to do is mission impossible. I suppose you could copy the data on to 15 thumb drives of 32GB each. But, you can't format a 500GB drive to FAT32.
Sorry, but you need to look a bit harder. In the past I've seen several articles on how to do it. But it's been a while. But I'm POSITIVE there are articles on how to do it. Some of the articles use various specialized utilities.already did. AT was my last hope : )