Wiping a hard drive is the act of completely removing all information and data on a computer. The reasons behind this may vary, such as completely reinstalling an operating system or removing data for security purposes, and the Mac OS Disk Utility tool provides the ability to erase all data on your MacBook Pro's hard drive. The utility includes options to write over the deleted data repeatedly, making it impossible to recover, depending on your preference.
Insert your Mac's installation CD into your MacBook Pro laptop, then shut it down.
Turn on your laptop and immediately hold down the "C" key until your laptop boots from the CD, displaying the installer screen. When the installer screen appears, click "Installer," then click "Open Disk Utilities."
Click on the name of the hard drive you want to erase (most commonly "Macintosh HD"), then click the "Erase" tab. Select "Mac OS Extended (Journaled)" from the "Volume Format" drop-down.
Select one of the available options from the deletion menu. If you're trying to delete everything completely, select "Zero all data," though if you want to be more thorough, you can select another option with multiple passes. The multiple passes option repeatedly overwrites the wiped data with random information, but if you select a high number of passes, the process will take a significantly longer amount of time.
Click "OK," then click "Erase."