How can I copy the OS X system image from primary HDD to new SSD?
I would try to open the enclosure of your external USB drive and replace it with the SSD to clone your data.
Simple hard drive cloning using Carbon Copy Cloner

Format the target drive with Disk Utiliy.app to Mac OS Extendend (Journaled) using the option Erase. This erases the drive and creates one partition across the entire disk.

Download and install Carbon Copy Cloner.
BTW: Developers need to eat! Therefore, I suggest making a small donation to Mike Bombich via Paypal.

In CCC configure Source Disk: Macintosh HD and Target Disk: your_formatted_disk. For cloning options choose Backup everything in order to make the target bootable. The time for cloning varies. It took me 105min to clone a 250GB Hitachi to a 500GB Seagate.


Swap the hard drives and boot into your new hard drive. Repair your disk using Disk Utility.


Source: credit to Mark West @ mac101.net