Open Disk Utility. Please See Answer 20985: How to access Disk Utility macOS 2. In the top menu bar, go to View, and choose Show All Devices. Select the upper level of the drive you would like to format and click the Erase button. Choose how you would like to format the drive. Enter a Name for your drive; Choose exFAT or MS-DOS (FAT. Top Level View of Formatting WD Elements for a Mac and a PC. Connect up your WD Elements drive to your Mac. You use Disk Utility. First to format your WD Elements external drive to Mac OS Extended (Journaled) file system. Then you quickly follow up by formatting to ExFAT. If you want to format a drive that will be used as your Mac’s startup disk, the procedure is a little different from formatting it for use as a secondary drive for storing data. Select the disk from the menu, select your language, then choose Disk Utility from the Utility drop-down menu and proceed to reformat it to the right settings. Then you can go back and install the OS.
Disk Utility User Guide
In Disk Utility on Mac, you can erase and reformat storage devices to use with your Mac. Erasing a storage device deletes everything on it.
If you have any files you want to save, copy them to another storage device.
Open the Disk Utility app on your Mac using one of the following methods, depending on the type of disk or volume you want to erase:
If you want to erase your startup disk: Start up from macOS Recovery, then choose Disk Utility from the Recovery window.
If you want to erase any other type of storage device: Double-click Disk Utility in the /Applications/Utilities folder.
Choose View > Show All Devices.
In the sidebar, select the storage device you want to erase, then click the Erase button .
Click the Scheme pop-up menu, then choose GUID Partition Map.
Click the Format pop-up menu, then choose a file system format.
Enter a name.
(Optional) If available, click Security Options, use the slider to choose how many times to write over the erased data, then click OK.
Secure erase options are available only for some types of storage devices. If the Security Options button is not available, Disk Utility cannot perform a secure erase on the storage device.
Click Erase, then click Done.
Note: With a solid-state drive (SSD), secure erase options are not available in Disk Utility. For more security, consider turning on FileVault encryption when you start using your SSD drive.