Hello, I am looking to sell my rMBP 15" and am curious how I would go about completely wiping the drive (similar to zeroing out a HDD). I have my new rMBP and was thinking of connecting the 2 using a ThunderBolt cable but am not sure if that would work. I have a USB drive with Yosemite on it but am not sure if I could completely wipe my primary partition and recovery using it. If there isn't a solution to wipe the drive completely, I may have no choice but to keep my SSD and part out the system (which I want to avoid). Thanks for the help!