How to Erase Memory on MacBooks

Attach the drive your wish to erase and format to your machine if it is not connected already.
Launch a Finder window, click 'Applications', then 'Utilities'. Double-click the 'Disk Utility' application shortcut.
Click a disk in the Volumes section. Select the Volume type from the 'Volume Format' drop-down box.
Click the 'Security Options' button, then click to select the 'Zero All Data' check box. Click 'OK' then click the 'Erase...' button.
VPS Hosting