For this protocol you need your new MacBook Pro which came with Lion installed (late 2011) and an older Macintosh capable of booting off earlier version of 10.6 such as the Mid 2009 MacBook Pro which I am using to run this protocol.
For this I used: New MacBook Pro 2.2 Ghz; 500GB internal (New Mac); Mid 2009 MacBook Pro running 10.6.8 (Old Mac); Retail 10.6.3 Installation DVD; Downloaded Mac 10.6.8.1 Combo Updater; Windows 7 Ultimate Installation DVD; Firewire 800 cable; 16GB USB stick.
I don’t like Lion very much so far, so am only giving it a token 50 GB partition, just enough to keep it installed and up to date to see how it develops. I’ll mainly be working in 10.6.8 as several of the applications I use regularly are running fine in 10.6 and I don’t want to mess with uncertainty during the work week. I only use Windows for a couple of applications and don’t need much storage there. Therefore, 10.6 gets the majority of my HD space, Windows 30GB and Lion 50GB.
On the new Mac:
1. Follow the instructions near the end of this article to redownload a Lion installer. http://support.apple.com/kb/HT4718
The instructions are near the end of the article. Since your mac came with Lion the download is free. HOWEVER, watch your wallet as the App store may not honor this freebie. I noticed it tried to charge me and I had to escalate to senior staff at customer care to get it corrected back to free.
Create a 10.7 installation DVD or create an installer on a USB stick. The stick will be faster to use in the future. In addition, if the stick is large enough (16GB or better) you can partition the stick into three, use one for your 10.7 installer, one for a 10.6.8.1 installer and the last little one for the 10.7.2 combo updater and the 10.6.8 combo updater ... keeping these up to date as time passes.
2. Launch Boot Camp Assistant, download and burn the apple drivers to disk. You need the Windows 7 installer disk for this. If you have trouble with this it isn't a big deal .... Step 4 of the Boot Camp v4 Installation and Set-up Guide tells you how to get the drivers again.
3. Quit Boot Camp Assistant after downloading the drivers. You may burn them to disk now or do it later.
4. Eject the Windows disk.
5. Shut down the new Mac then start it up in Target Disk Mode (Hold down the “T” key right after poking the power button. Hold the “T” key down until you see the Firewire symbol floating around on the screen.
6. Plug in a firewire cable to the new mac, then into the old mac.
On the old Mac:
5. Launch Disk Utility and ERASE your new Mac, then quit disk utility.
6. Visit this URL for a more comprehensive description and background discussing the terminal commands that follow:
http://www.tech-recipes.com/rx/9839/how-to-manually-partition-boot-camp-your-mac -for-windows-7/
Launch Terminal
issue this command followed by a return:
diskutil list
This will provide you the addresses of the storage devices and partitions which exist on your old mac and the new mac and any other storage devices you have connected or DVD’s which you have inserted. It will look something like this, which is an example which has only two storage devices mounted:

Make note of the disk IDENTIFIER for the main disk of your New Mac. The example above shows only my Old Mac with an additional 16GB USB stick mounted on it. Note that my old Mac is disk0 in this example. Were my New Mac also mounted it would have a scheme beginning with disk2 if it were added to the example above.
So, assuming my new mac to be mounted and identified as disk2, then I issued the following command in Terminal:
diskutil partitiondisk /dev/disk2 3 MS-DOS WIN7 30G JHFS+ MAC10.7 50G JHFS+ MAC10.6.8 420G
Which resulted in the recently erased new mac (disk2) being partitioned into three partitions, the first visible partition being a 30GB MS-DOS (Fat 32) partition named “WIN7”, the second a 50GB GUID MacOSX Extended Journaled partition named “MAC10.7” and the third a 420GB GUID MacOSX Extended Journaled partition named “MAC10.6.8”. These are all now empty partitions, ready for use. Note: When you see these again they will be shifted numerically because the OS puts a small partition ahead of the ones which are visible. Also 10.7 will also add a small on to the MAC10.7 partition when you install Lion into that partition.
Using the Terminal command above, substitute YOUR new mac disk number for the 2 in my example. If you want more space for Windows 7 make that partition larger, others smaller as you wish. My example is a 500 GB drive being partitioned into three with one of those being intended for my Windows 7 installation.
7, After Terminal has successfully reported partitioning your new mac drive,
issue a list command again and take note of which partitions are which:
diskutil list
If you followed the same command structure I used in the example above the Windows partition is now number 2 on your new Mac.
After making your notes, quit terminal.
8. Eject your Target Disk and disconnect the cables between your new mac and your old mac.
9. Hold down the power button on your new mac to turn it off.
10. Get out your Windows 7 Installation DVD and slip it into your new mac as you restart it. The Windows 7 installer will boot, follow the instructions in the Apple Boot Camp version 4 guide to install Windows 7. Know the size and location of the partition you are going to install Windows 7 into. When you get to the phase of identifying the location to install Windows 7, be sure to chose the right one then follow the apple instructions to format that partition for Windows. The Windows 7 installer will change the format from Fat32 to NTSF, then you will continue with your installation.
11. After the Windows 7 installation completes, restart your computer and use the “option” key held down during start to allow selection of an alternate boot device.
12. Insert your 10.7 installation device ….. USB stick or DVD and wait for it to appear in the selection window. Choose it and continue the start-up.
13. Install 10.7 completely, then eject and remove the USB stick or DVD
14. Restart in Target Disk mode.
15. Reconnect your new mac to your old mac with the firewire cable.
16. If you have extracted a dmg of the Snow Leopard retail installer disk and put it onto your USB stick, insert the stick otherwise, insert the Snow Leopard installer DVD and run the 10.6 installer from whichever device you have inserted.
17. Chose your 10.6 partition on the new mac and install 10.6.3 from the retail source.
18. After 10.6 installation has completed, Restart from your old mac (Option key during reboot), continue restart from your old mac.
19. Run the 10.6.8.1 combo updater which you downloaded from apple on your new mac 10.6 installation.
20. After the combo update completes eject the target disk volumes and USB volumes and then disconnect the firewire cables.
21. Restart your new mac with option key down. Select your 10.6.8 startup partition and continue the start.
22. Re run the 10.6.8.1 combo updater natively on the new mac. Run disk utility and repair permissions. Run Software update and do any additional updates. Run disk utility and repair permissions again.
23. Re start, option key down … select the 10.7 installation and run the most recent combo updater on it. Right now that is 10.7.2. Run software update and do whatever updating comes to visit. Run disk utility and repair permissions.
24. Re start, option key down and boot into Windows. Update and set-up Windows, using the Windows Boot Camp to install your apple drivers from the drivers CD you previously created. Update Windows and Boot Camp again ….
Here is what diskutil shows on my new mac after all of this:

Whew …. Get back to work and enjoy your new Triple Boot MacBook Pro!