Built right into OS X Lion, Lion Recovery lets you repair disks or reinstall OS X Lion without the need for a physical disc. The Lion Recovery Disk Assistant lets you create Lion Recovery on an external drive that has all of the same capabilities as the built-in Lion Recovery: reinstall Lion, repair the disk using Disk Utility, restore from a Time Machine backup, or browse the web with Safari.
Note: In order to create an external Lion Recovery using the Lion Recovery Assistant, the Mac must have an existing Recovery HD.
1. Download Lion Recovery Disk Assistant
2. Double-click on the .dmg file to open it
3. Double-click on the Recovery Disk Assistant icon to open it.
4. Read the software license agreement ( if you’re one of ‘them’ ) and click on ‘Agree’
5. Get your USB drive ( at least 4 gigs ) and plug it in. NOTE: all data on the drive will be erased
6. Select the drive and click on ‘Continue’
7. Now everything will be done automatically. The only thing you will need to do is input your Mac’s password when prompted. The process takes about 30-50 seconds
8. That’s it, you’re done. To use the recovery disk, restart your computer, press the alt/option key after the chime sound and select the disk