I picked up a 2015 rMBP during the Best Buy sale earlier this week. The screen has some yellow tint on the left half and some poor backlighting along the lower right part. I want to do an exchange in hopes of getting one with a better screen. What is the right course of action to erase my data and set to back to "factory defaults" before exchanging it? I set it up from a fresh install, so the only things on it are my google accounts, iTunes account is linked, some pictures, and browser history.