Formatting to Fat32

I want to format my 1tb passport to fat32 to make it compatible with windows eight and mac but I’m rubbish with technology so what software should I download to reformat my device?

Try the suggestions on the following article:

How to format a WD external hard drive in FAT32 (to use in Windows or Mac OSX)

http://wdc.custhelp.com/app/answers/detail/a_id/291