Otherwise, select one of the formats from MS-DOS FAT (FAT32). Then choose the format Mac OS extended daily if you intend to use your hard drive exclusively on Mac. Now if you want to change the name of the external drive, enter it in the field name and choose the file system format through the drop down menu next to the option format. In the opened new window, find and select the name of the hard disk, and press the start button, located at the top. Alternatively, click on the item vai located in the top menu bar, select or Utility and press the Utility Disk option. To format your hard drive through Mac, press the icon magnifying glass present at the top right, type disk Utility in the search field.