I'm ordering a rMBP, and need to transfer my files from my old MBP to the new one when it comes in. Here's the catch, I plan to move my iTunes and iPhoto libraries off my internal hard drive and onto an external because I won't have enough space on the 256gb hard drive and I can't justify spending an extra $600 for the next size up. What is the best, easiest, way to do this? I currently have 500gb of files, about 300gb of which are these two libraries. Does migration assistant allow you to specify where things go, or is there a better solution? I'd really like to not use migration assistant at all, and just manually put the files I want on the new computer, but don't want to screw up those libraries and lose my data. Advice? I have a 2tb USB3 drive where these files will be residing.