There are many good options when it comes to choosing which application will handle your imaging process; for this guide I will be using SuperDuper!.

1. Connect your target machine to the source machine via firewire. Turn your target machine on and hold down the 'T' key to boot into target mode. The remainder of the instructions should be executed from the source machine.
2. Open SuperDuper!, if the lock at the lower left hand side is in the locked position, click to unlock it and authenticate the application.
3. In the "Copy" field select your drive. 
4. In the "to" field select the drive on the machine in target mode that you wish to clone to.
5. Click "Copy Now".
6. If no errors are thrown once it has completed, boot the target machine and verify that the image has carried over correctly.