Here are the slightly butchered instructions from my tutorial from the beginning, which I've tested a couple of times on all of my Macs that came with Lion. I should have a video version of this by Friday.
Connect an external USB flash drive, open Disk Utility and once the external drive appears, select it and make sure that it has the correct partition scheme (GUID Partition Scheme).
⏎ - means press enter
Open Terminal by going into Applications ⇢ Utilities ⇢ Terminal.app
In the Terminal window type in
Code:
diskutil list ⏎You will see a list of all of the partitions on the hard drive. Look for the line item that says Apple_Boot Recovery HD and take note of the identifier column.
Now type:
Code:
diskutil mount readOnly /dev/disk0s3 ⏎Substitute disk0s3 for whatever you see in the identifier column when you executed “diskutil list” (it should be the same unless you’ve been changing your partitions).
Just one more bit of text to type (all on one line):
Code:
hdiutil attach "/Volumes/Recovery HD/com.apple.recovery.boot/BaseSystem.dmg" ⏎This will mount the BaseSystem.dmg file, which contains the Lion install application. “Mac OS X Base System” will now either open automatically or you will need to navigate to it in Finder, by clicking on “Mac OS X Base System” in the sidebar and then double click on Install Mac OS X Lion. Unfortunately this does not contain the entire installation so it will connect to Apple’s server and download the installation files that it needs.
Follow the prompts by hitting Continue a couple of times and then agree to the Terms and Conditions.
On the screen where you’re prompted where OS X will be installed, click on “Show All Disks...”. You’ll need a temporary place to store the files that the installer application will download. Even though you will be using the USB flash drive to create a bootable installer once the download is complete, it’s perfectly fine to use the same flash drive to store these install files in the mean time, if it has a capacity of at least 10 GB. Or you can use another flash drive or an external drive, if you have a spare.
The install process will download around 4 GBs so it may take some time, depending on how fast your Internet connection is. The problem here is that once the files are downloaded, the installer application will try to restart automatically and continue the installation process. It will also delete the files you’ve just downloaded! You can either watch the process as it nears completion and force quit it before it restarts, or you can attempt to cancel the automated restart.
To cancel the automated restart, open an application that does not use autosave, for e.g. Microsoft Word, and create a new document, Type something into the document and do not save. When the install process will try to restart, the unsaved document will prevent this. Another alternative is to open Disk Utility and then select your storage device in the left pane and click on the Partition tab in the right pane. Then click on the + button. Do not click Apply and simply leave Disk Utility in the background during the download. This will prevent the installer from restarting. Disk Utility will prompt whether you want to quit. Leave the Disk Utility window and follow the next paragraphs until you’re ready to create a bootable Lion install disk.
Whichever option you take, once the download process is complete, do not close the installer application normally or it will delete the files it has just downloaded - you have to do a force quit. Hit ⌘⌥⎋ , or click on menu and click “Force Quit...”. Make sure that “Install Mac OS X Lion” is selected and click “Force Quit”.
Open Finder and navigate to the external disk where you chose to install Lion.
Note: If you’re using one USB flash drive, then copy the “Mac OS X Install Data” folder to somewhere on your internal storage first, for e.g. the desktop.
Open the “Mac OS X Install Data” folder and double click on InstallESD.dmg. Close the window that appears and open Disk Utility.
If you used Disk Utility to prevent the restart, you can now click on “Don’t Quit” and click OK on the dialog informing you that the restart has been cancelled. Click Revert in the Partition tab and proceed.
Connect an external USB flash drive, if one isn’t connected already. Click on “Mac OS X Install ESD” in the left pane, then click on the Restore tab in the right pane. Make sure that “Mac OS X Install ESD” is set as the source. Drag the USB flash drive’s partition into the Destination box and click Restore. Do not drag in the flash device itself - make sure you’re dragging in the partition. A confirmation dialog will appear asking whether you definitely want to do this. Read it carefully to check that your source and destination are correct, then click Erase, enter your credentials and wait for the process to complete. Eject InstallESD.dmg and then quit Disk Utility.
